From 0a55fa14f462169bbd8a8de623804f039854f95f Mon Sep 17 00:00:00 2001
From: dartraiden
-The HTML documentation for PCRE consists of a number of pages that are listed
-below in alphabetical order. If you are new to PCRE, please read the first one
-first.
-
-There are also individual pages that summarize the interface for each function
-in the library. There is a single page for each triple of 8-bit/16-bit/32-bit
-functions.
-
-Return to the PCRE index page.
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-pcre-config [--prefix] [--exec-prefix] [--version] [--libs]
- [--libs16] [--libs32] [--libs-cpp] [--libs-posix]
- [--cflags] [--cflags-posix]
-
-pcre-config returns the configuration of the installed PCRE
-libraries and the options required to compile a program to use them. Some of
-the options apply only to the 8-bit, or 16-bit, or 32-bit libraries,
-respectively, and are
-not available if only one of those libraries has been built. If an unavailable
-option is encountered, the "usage" information is output.
-
---prefix
-Writes the directory prefix used in the PCRE installation for architecture
-independent files (/usr on many systems, /usr/local on some
-systems) to the standard output.
-
---exec-prefix
-Writes the directory prefix used in the PCRE installation for architecture
-dependent files (normally the same as --prefix) to the standard output.
-
---version
-Writes the version number of the installed PCRE libraries to the standard
-output.
-
---libs
-Writes to the standard output the command line options required to link
-with the 8-bit PCRE library (-lpcre on many systems).
-
---libs16
-Writes to the standard output the command line options required to link
-with the 16-bit PCRE library (-lpcre16 on many systems).
-
---libs32
-Writes to the standard output the command line options required to link
-with the 32-bit PCRE library (-lpcre32 on many systems).
-
---libs-cpp
-Writes to the standard output the command line options required to link with
-PCRE's C++ wrapper library (-lpcrecpp -lpcre on many
-systems).
-
---libs-posix
-Writes to the standard output the command line options required to link with
-PCRE's POSIX API wrapper library (-lpcreposix -lpcre on many
-systems).
-
---cflags
-Writes to the standard output the command line options required to compile
-files that use PCRE (this may include some -I options, but is blank on
-many systems).
-
---cflags-posix
-Writes to the standard output the command line options required to compile
-files that use PCRE's POSIX API wrapper library (this may include some -I
-options, but is blank on many systems).
-
-pcre(3)
-
-This manual page was originally written by Mark Baker for the Debian GNU/Linux
-system. It has been subsequently revised as a generic PCRE man page.
-
-Last updated: 24 June 2012
-
-Return to the PCRE index page.
-
-Return to the PCRE index page.
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-This document relates to PCRE releases that use the original API,
-with library names libpcre, libpcre16, and libpcre32. January 2015 saw the
-first release of a new API, known as PCRE2, with release numbers starting at
-10.00 and library names libpcre2-8, libpcre2-16, and libpcre2-32. The old
-libraries (now called PCRE1) are still being maintained for bug fixes, but
-there will be no new development. New projects are advised to use the new PCRE2
-libraries.
-
-The PCRE library is a set of functions that implement regular expression
-pattern matching using the same syntax and semantics as Perl, with just a few
-differences. Some features that appeared in Python and PCRE before they
-appeared in Perl are also available using the Python syntax, there is some
-support for one or two .NET and Oniguruma syntax items, and there is an option
-for requesting some minor changes that give better JavaScript compatibility.
-
-Starting with release 8.30, it is possible to compile two separate PCRE
-libraries: the original, which supports 8-bit character strings (including
-UTF-8 strings), and a second library that supports 16-bit character strings
-(including UTF-16 strings). The build process allows either one or both to be
-built. The majority of the work to make this possible was done by Zoltan
-Herczeg.
-
-Starting with release 8.32 it is possible to compile a third separate PCRE
-library that supports 32-bit character strings (including UTF-32 strings). The
-build process allows any combination of the 8-, 16- and 32-bit libraries. The
-work to make this possible was done by Christian Persch.
-
-The three libraries contain identical sets of functions, except that the names
-in the 16-bit library start with pcre16_ instead of pcre_, and the
-names in the 32-bit library start with pcre32_ instead of pcre_. To
-avoid over-complication and reduce the documentation maintenance load, most of
-the documentation describes the 8-bit library, with the differences for the
-16-bit and 32-bit libraries described separately in the
-pcre16
-and
-pcre32
-pages. References to functions or structures of the form pcre[16|32]_xxx
-should be read as meaning "pcre_xxx when using the 8-bit library,
-pcre16_xxx when using the 16-bit library, or pcre32_xxx when using
-the 32-bit library".
-
-The current implementation of PCRE corresponds approximately with Perl 5.12,
-including support for UTF-8/16/32 encoded strings and Unicode general category
-properties. However, UTF-8/16/32 and Unicode support has to be explicitly
-enabled; it is not the default. The Unicode tables correspond to Unicode
-release 6.3.0.
-
-In addition to the Perl-compatible matching function, PCRE contains an
-alternative function that matches the same compiled patterns in a different
-way. In certain circumstances, the alternative function has some advantages.
-For a discussion of the two matching algorithms, see the
-pcrematching
-page.
-
-PCRE is written in C and released as a C library. A number of people have
-written wrappers and interfaces of various kinds. In particular, Google Inc.
-have provided a comprehensive C++ wrapper for the 8-bit library. This is now
-included as part of the PCRE distribution. The
-pcrecpp
-page has details of this interface. Other people's contributions can be found
-in the Contrib directory at the primary FTP site, which is:
-ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre
-
-Details of exactly which Perl regular expression features are and are not
-supported by PCRE are given in separate documents. See the
-pcrepattern
-and
-pcrecompat
-pages. There is a syntax summary in the
-pcresyntax
-page.
-
-Some features of PCRE can be included, excluded, or changed when the library is
-built. The
-pcre_config()
-function makes it possible for a client to discover which features are
-available. The features themselves are described in the
-pcrebuild
-page. Documentation about building PCRE for various operating systems can be
-found in the
-README
-and
-NON-AUTOTOOLS_BUILD
-files in the source distribution.
-
-The libraries contains a number of undocumented internal functions and data
-tables that are used by more than one of the exported external functions, but
-which are not intended for use by external callers. Their names all begin with
-"_pcre_" or "_pcre16_" or "_pcre32_", which hopefully will not provoke any name
-clashes. In some environments, it is possible to control which external symbols
-are exported when a shared library is built, and in these cases the
-undocumented symbols are not exported.
-
-If you are using PCRE in a non-UTF application that permits users to supply
-arbitrary patterns for compilation, you should be aware of a feature that
-allows users to turn on UTF support from within a pattern, provided that PCRE
-was built with UTF support. For example, an 8-bit pattern that begins with
-"(*UTF8)" or "(*UTF)" turns on UTF-8 mode, which interprets patterns and
-subjects as strings of UTF-8 characters instead of individual 8-bit characters.
-This causes both the pattern and any data against which it is matched to be
-checked for UTF-8 validity. If the data string is very long, such a check might
-use sufficiently many resources as to cause your application to lose
-performance.
-
-One way of guarding against this possibility is to use the
-pcre_fullinfo() function to check the compiled pattern's options for UTF.
-Alternatively, from release 8.33, you can set the PCRE_NEVER_UTF option at
-compile time. This causes an compile time error if a pattern contains a
-UTF-setting sequence.
-
-If your application is one that supports UTF, be aware that validity checking
-can take time. If the same data string is to be matched many times, you can use
-the PCRE_NO_UTF[8|16|32]_CHECK option for the second and subsequent matches to
-save redundant checks.
-
-Another way that performance can be hit is by running a pattern that has a very
-large search tree against a string that will never match. Nested unlimited
-repeats in a pattern are a common example. PCRE provides some protection
-against this: see the PCRE_EXTRA_MATCH_LIMIT feature in the
-pcreapi
-page.
-
-The user documentation for PCRE comprises a number of different sections. In
-the "man" format, each of these is a separate "man page". In the HTML format,
-each is a separate page, linked from the index page. In the plain text format,
-the descriptions of the pcregrep and pcretest programs are in files
-called pcregrep.txt and pcretest.txt, respectively. The remaining
-sections, except for the pcredemo section (which is a program listing),
-are concatenated in pcre.txt, for ease of searching. The sections are as
-follows:
-Perl-compatible Regular Expressions (PCRE)
-
-
-
-
-
-pcre
- Introductory page
-
-pcre-config
- Information about the installation configuration
-
-pcre16
- Discussion of the 16-bit PCRE library
-
-pcre32
- Discussion of the 32-bit PCRE library
-
-pcreapi
- PCRE's native API
-
-pcrebuild
- Building PCRE
-
-pcrecallout
- The callout facility
-
-pcrecompat
- Compability with Perl
-
-pcrecpp
- The C++ wrapper for the PCRE library
-
-pcredemo
- A demonstration C program that uses the PCRE library
-
-pcregrep
- The pcregrep command
-
-pcrejit
- Discussion of the just-in-time optimization support
-
-pcrelimits
- Details of size and other limits
-
-pcrematching
- Discussion of the two matching algorithms
-
-pcrepartial
- Using PCRE for partial matching
-
-pcrepattern
- Specification of the regular expressions supported by PCRE
-
-pcreperform
- Some comments on performance
-
-pcreposix
- The POSIX API to the PCRE 8-bit library
-
-pcreprecompile
- How to save and re-use compiled patterns
-
-pcresample
- Discussion of the pcredemo program
-
-pcrestack
- Discussion of PCRE's stack usage
-
-pcresyntax
- Syntax quick-reference summary
-
-pcretest
- The pcretest command for testing PCRE
-pcreunicode
- Discussion of Unicode and UTF-8/UTF-16/UTF-32 support
-
-
-
-
diff --git a/libs/Pcre16/docs/doc/html/pcre-config.html b/libs/Pcre16/docs/doc/html/pcre-config.html
deleted file mode 100644
index 56a8060492..0000000000
--- a/libs/Pcre16/docs/doc/html/pcre-config.html
+++ /dev/null
@@ -1,109 +0,0 @@
-
-
-
-
-pcre_assign_jit_stack
- Assign stack for JIT matching
-
-pcre_compile
- Compile a regular expression
-
-pcre_compile2
- Compile a regular expression (alternate interface)
-
-pcre_config
- Show build-time configuration options
-
-pcre_copy_named_substring
- Extract named substring into given buffer
-
-pcre_copy_substring
- Extract numbered substring into given buffer
-
-pcre_dfa_exec
- Match a compiled pattern to a subject string
- (DFA algorithm; not Perl compatible)
-
-pcre_exec
- Match a compiled pattern to a subject string
- (Perl compatible)
-
-pcre_free_study
- Free study data
-
-pcre_free_substring
- Free extracted substring
-
-pcre_free_substring_list
- Free list of extracted substrings
-
-pcre_fullinfo
- Extract information about a pattern
-
-pcre_get_named_substring
- Extract named substring into new memory
-
-pcre_get_stringnumber
- Convert captured string name to number
-
-pcre_get_stringtable_entries
- Find table entries for given string name
-
-pcre_get_substring
- Extract numbered substring into new memory
-
-pcre_get_substring_list
- Extract all substrings into new memory
-
-pcre_jit_exec
- Fast path interface to JIT matching
-
-pcre_jit_stack_alloc
- Create a stack for JIT matching
-
-pcre_jit_stack_free
- Free a JIT matching stack
-
-pcre_maketables
- Build character tables in current locale
-
-pcre_pattern_to_host_byte_order
- Convert compiled pattern to host byte order if necessary
-
-pcre_refcount
- Maintain reference count in compiled pattern
-
-pcre_study
- Study a compiled pattern
-
-pcre_utf16_to_host_byte_order
- Convert UTF-16 string to host byte order if necessary
-
-pcre_utf32_to_host_byte_order
- Convert UTF-32 string to host byte order if necessary
-pcre_version
- Return PCRE version and release date pcre-config man page
-
-
SYNOPSIS
-
DESCRIPTION
-
OPTIONS
-
SEE ALSO
-
AUTHOR
-
REVISION
-
-pcre man page
-
-
PLEASE TAKE NOTE
-
INTRODUCTION
-
SECURITY CONSIDERATIONS
-
USER DOCUMENTATION
-
- pcre this document
- pcre-config show PCRE installation configuration information
- pcre16 details of the 16-bit library
- pcre32 details of the 32-bit library
- pcreapi details of PCRE's native C API
- pcrebuild building PCRE
- pcrecallout details of the callout feature
- pcrecompat discussion of Perl compatibility
- pcrecpp details of the C++ wrapper for the 8-bit library
- pcredemo a demonstration C program that uses PCRE
- pcregrep description of the pcregrep command (8-bit only)
- pcrejit discussion of the just-in-time optimization support
- pcrelimits details of size and other limits
- pcrematching discussion of the two matching algorithms
- pcrepartial details of the partial matching facility
- pcrepattern syntax and semantics of supported regular expressions
- pcreperform discussion of performance issues
- pcreposix the POSIX-compatible C API for the 8-bit library
- pcreprecompile details of saving and re-using precompiled patterns
- pcresample discussion of the pcredemo program
- pcrestack discussion of stack usage
- pcresyntax quick syntax reference
- pcretest description of the pcretest testing command
- pcreunicode discussion of Unicode and UTF-8/16/32 support
-
-In the "man" and HTML formats, there is also a short page for each C library
-function, listing its arguments and results.
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Putting an actual email address here seems to have been a spam magnet, so I've -taken it away. If you want to email me, use my two initials, followed by the -two digits 10, at the domain cam.ac.uk. -
-
-Last updated: 10 February 2015
-
-Copyright © 1997-2015 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre16.html b/libs/Pcre16/docs/doc/html/pcre16.html deleted file mode 100644 index f00859f052..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre16.html +++ /dev/null @@ -1,384 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcre.h> -
-
-pcre16 *pcre16_compile(PCRE_SPTR16 pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre16 *pcre16_compile2(PCRE_SPTR16 pattern, int options,
- int *errorcodeptr,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre16_extra *pcre16_study(const pcre16 *code, int options,
- const char **errptr);
-
-
-void pcre16_free_study(pcre16_extra *extra);
-
-
-int pcre16_exec(const pcre16 *code, const pcre16_extra *extra,
- PCRE_SPTR16 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-
-int pcre16_dfa_exec(const pcre16 *code, const pcre16_extra *extra,
- PCRE_SPTR16 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-int pcre16_copy_named_substring(const pcre16 *code,
- PCRE_SPTR16 subject, int *ovector,
- int stringcount, PCRE_SPTR16 stringname,
- PCRE_UCHAR16 *buffer, int buffersize);
-
-
-int pcre16_copy_substring(PCRE_SPTR16 subject, int *ovector,
- int stringcount, int stringnumber, PCRE_UCHAR16 *buffer,
- int buffersize);
-
-
-int pcre16_get_named_substring(const pcre16 *code,
- PCRE_SPTR16 subject, int *ovector,
- int stringcount, PCRE_SPTR16 stringname,
- PCRE_SPTR16 *stringptr);
-
-
-int pcre16_get_stringnumber(const pcre16 *code,
-" PCRE_SPTR16 name);
-
-
-int pcre16_get_stringtable_entries(const pcre16 *code,
- PCRE_SPTR16 name, PCRE_UCHAR16 **first, PCRE_UCHAR16 **last);
-
-
-int pcre16_get_substring(PCRE_SPTR16 subject, int *ovector,
- int stringcount, int stringnumber,
- PCRE_SPTR16 *stringptr);
-
-
-int pcre16_get_substring_list(PCRE_SPTR16 subject,
- int *ovector, int stringcount, PCRE_SPTR16 **listptr);
-
-
-void pcre16_free_substring(PCRE_SPTR16 stringptr);
-
-
-void pcre16_free_substring_list(PCRE_SPTR16 *stringptr);
-
-pcre16_jit_stack *pcre16_jit_stack_alloc(int startsize, int maxsize);
-
-
-void pcre16_jit_stack_free(pcre16_jit_stack *stack);
-
-
-void pcre16_assign_jit_stack(pcre16_extra *extra,
- pcre16_jit_callback callback, void *data);
-
-
-const unsigned char *pcre16_maketables(void);
-
-
-int pcre16_fullinfo(const pcre16 *code, const pcre16_extra *extra,
- int what, void *where);
-
-
-int pcre16_refcount(pcre16 *code, int adjust);
-
-
-int pcre16_config(int what, void *where);
-
-
-const char *pcre16_version(void);
-
-
-int pcre16_pattern_to_host_byte_order(pcre16 *code,
- pcre16_extra *extra, const unsigned char *tables);
-
-void *(*pcre16_malloc)(size_t);
-
-
-void (*pcre16_free)(void *);
-
-
-void *(*pcre16_stack_malloc)(size_t);
-
-
-void (*pcre16_stack_free)(void *);
-
-
-int (*pcre16_callout)(pcre16_callout_block *);
-
-int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *output, - PCRE_SPTR16 input, int length, int *byte_order, - int keep_boms); -
--Starting with release 8.30, it is possible to compile a PCRE library that -supports 16-bit character strings, including UTF-16 strings, as well as or -instead of the original 8-bit library. The majority of the work to make this -possible was done by Zoltan Herczeg. The two libraries contain identical sets -of functions, used in exactly the same way. Only the names of the functions and -the data types of their arguments and results are different. To avoid -over-complication and reduce the documentation maintenance load, most of the -PCRE documentation describes the 8-bit library, with only occasional references -to the 16-bit library. This page describes what is different when you use the -16-bit library. -
--WARNING: A single application can be linked with both libraries, but you must -take care when processing any particular pattern to use functions from just one -library. For example, if you want to study a pattern that was compiled with -pcre16_compile(), you must do so with pcre16_study(), not -pcre_study(), and you must free the study data with -pcre16_free_study(). -
--There is only one header file, pcre.h. It contains prototypes for all the -functions in all libraries, as well as definitions of flags, structures, error -codes, etc. -
--In Unix-like systems, the 16-bit library is called libpcre16, and can -normally be accesss by adding -lpcre16 to the command for linking an -application that uses PCRE. -
--In the 8-bit library, strings are passed to PCRE library functions as vectors -of bytes with the C type "char *". In the 16-bit library, strings are passed as -vectors of unsigned 16-bit quantities. The macro PCRE_UCHAR16 specifies an -appropriate data type, and PCRE_SPTR16 is defined as "const PCRE_UCHAR16 *". In -very many environments, "short int" is a 16-bit data type. When PCRE is built, -it defines PCRE_UCHAR16 as "unsigned short int", but checks that it really is a -16-bit data type. If it is not, the build fails with an error message telling -the maintainer to modify the definition appropriately. -
--The types of the opaque structures that are used for compiled 16-bit patterns -and JIT stacks are pcre16 and pcre16_jit_stack respectively. The -type of the user-accessible structure that is returned by pcre16_study() -is pcre16_extra, and the type of the structure that is used for passing -data to a callout function is pcre16_callout_block. These structures -contain the same fields, with the same names, as their 8-bit counterparts. The -only difference is that pointers to character strings are 16-bit instead of -8-bit types. -
--For every function in the 8-bit library there is a corresponding function in -the 16-bit library with a name that starts with pcre16_ instead of -pcre_. The prototypes are listed above. In addition, there is one extra -function, pcre16_utf16_to_host_byte_order(). This is a utility function -that converts a UTF-16 character string to host byte order if necessary. The -other 16-bit functions expect the strings they are passed to be in host byte -order. -
--The input and output arguments of -pcre16_utf16_to_host_byte_order() may point to the same address, that is, -conversion in place is supported. The output buffer must be at least as long as -the input. -
--The length argument specifies the number of 16-bit data units in the -input string; a negative value specifies a zero-terminated string. -
--If byte_order is NULL, it is assumed that the string starts off in host -byte order. This may be changed by byte-order marks (BOMs) anywhere in the -string (commonly as the first character). -
--If byte_order is not NULL, a non-zero value of the integer to which it -points means that the input starts off in host byte order, otherwise the -opposite order is assumed. Again, BOMs in the string can change this. The final -byte order is passed back at the end of processing. -
--If keep_boms is not zero, byte-order mark characters (0xfeff) are copied -into the output string. Otherwise they are discarded. -
--The result of the function is the number of 16-bit units placed into the output -buffer, including the zero terminator if the string was zero-terminated. -
--The lengths and starting offsets of subject strings must be specified in 16-bit -data units, and the offsets within subject strings that are returned by the -matching functions are in also 16-bit units rather than bytes. -
--The name-to-number translation table that is maintained for named subpatterns -uses 16-bit characters. The pcre16_get_stringtable_entries() function -returns the length of each entry in the table as the number of 16-bit data -units. -
--There are two new general option names, PCRE_UTF16 and PCRE_NO_UTF16_CHECK, -which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In -fact, these new options define the same bits in the options word. There is a -discussion about the -validity of UTF-16 strings -in the -pcreunicode -page. -
--For the pcre16_config() function there is an option PCRE_CONFIG_UTF16 -that returns 1 if UTF-16 support is configured, otherwise 0. If this option is -given to pcre_config() or pcre32_config(), or if the -PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF32 option is given to pcre16_config(), -the result is the PCRE_ERROR_BADOPTION error. -
--In 16-bit mode, when PCRE_UTF16 is not set, character values are treated in the -same way as in 8-bit, non UTF-8 mode, except, of course, that they can range -from 0 to 0xffff instead of 0 to 0xff. Character types for characters less than -0xff can therefore be influenced by the locale in the same way as before. -Characters greater than 0xff have only one case, and no "type" (such as letter -or digit). -
--In UTF-16 mode, the character code is Unicode, in the range 0 to 0x10ffff, with -the exception of values in the range 0xd800 to 0xdfff because those are -"surrogate" values that are used in pairs to encode values greater than 0xffff. -
--A UTF-16 string can indicate its endianness by special code knows as a -byte-order mark (BOM). The PCRE functions do not handle this, expecting strings -to be in host byte order. A utility function called -pcre16_utf16_to_host_byte_order() is provided to help with this (see -above). -
--The errors PCRE_ERROR_BADUTF16_OFFSET and PCRE_ERROR_SHORTUTF16 correspond to -their 8-bit counterparts. The error PCRE_ERROR_BADMODE is given when a compiled -pattern is passed to a function that processes patterns in the other -mode, for example, if a pattern compiled with pcre_compile() is passed to -pcre16_exec(). -
--There are new error codes whose names begin with PCRE_UTF16_ERR for invalid -UTF-16 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that -are described in the section entitled -"Reason codes for invalid UTF-8 strings" -in the main -pcreapi -page. The UTF-16 errors are: -
- PCRE_UTF16_ERR1 Missing low surrogate at end of string - PCRE_UTF16_ERR2 Invalid low surrogate follows high surrogate - PCRE_UTF16_ERR3 Isolated low surrogate - PCRE_UTF16_ERR4 Non-character -- -
-If there is an error while compiling a pattern, the error text that is passed -back by pcre16_compile() or pcre16_compile2() is still an 8-bit -character string, zero-terminated. -
--The subject and mark fields in the callout block that is passed to -a callout function point to 16-bit vectors. -
--The pcretest program continues to operate with 8-bit input and output -files, but it can be used for testing the 16-bit library. If it is run with the -command line option -16, patterns and subject strings are converted from -8-bit to 16-bit before being passed to PCRE, and the 16-bit library functions -are used instead of the 8-bit ones. Returned 16-bit strings are converted to -8-bit for output. If both the 8-bit and the 32-bit libraries were not compiled, -pcretest defaults to 16-bit and the -16 option is ignored. -
--When PCRE is being built, the RunTest script that is called by "make -check" uses the pcretest -C option to discover which of the 8-bit, -16-bit and 32-bit libraries has been built, and runs the tests appropriately. -
--Not all the features of the 8-bit library are available with the 16-bit -library. The C++ and POSIX wrapper functions support only the 8-bit library, -and the pcregrep program is at present 8-bit only. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 May 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre32.html b/libs/Pcre16/docs/doc/html/pcre32.html deleted file mode 100644 index f96876e750..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre32.html +++ /dev/null @@ -1,382 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcre.h> -
-
-pcre32 *pcre32_compile(PCRE_SPTR32 pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre32 *pcre32_compile2(PCRE_SPTR32 pattern, int options,
- int *errorcodeptr,
- const unsigned char *tableptr);
-
-
-pcre32_extra *pcre32_study(const pcre32 *code, int options,
- const char **errptr);
-
-
-void pcre32_free_study(pcre32_extra *extra);
-
-
-int pcre32_exec(const pcre32 *code, const pcre32_extra *extra,
- PCRE_SPTR32 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-
-int pcre32_dfa_exec(const pcre32 *code, const pcre32_extra *extra,
- PCRE_SPTR32 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-int pcre32_copy_named_substring(const pcre32 *code,
- PCRE_SPTR32 subject, int *ovector,
- int stringcount, PCRE_SPTR32 stringname,
- PCRE_UCHAR32 *buffer, int buffersize);
-
-
-int pcre32_copy_substring(PCRE_SPTR32 subject, int *ovector,
- int stringcount, int stringnumber, PCRE_UCHAR32 *buffer,
- int buffersize);
-
-
-int pcre32_get_named_substring(const pcre32 *code,
- PCRE_SPTR32 subject, int *ovector,
- int stringcount, PCRE_SPTR32 stringname,
- PCRE_SPTR32 *stringptr);
-
-
-int pcre32_get_stringnumber(const pcre32 *code,
- PCRE_SPTR32 name);
-
-
-int pcre32_get_stringtable_entries(const pcre32 *code,
- PCRE_SPTR32 name, PCRE_UCHAR32 **first, PCRE_UCHAR32 **last);
-
-
-int pcre32_get_substring(PCRE_SPTR32 subject, int *ovector,
- int stringcount, int stringnumber,
- PCRE_SPTR32 *stringptr);
-
-
-int pcre32_get_substring_list(PCRE_SPTR32 subject,
- int *ovector, int stringcount, PCRE_SPTR32 **listptr);
-
-
-void pcre32_free_substring(PCRE_SPTR32 stringptr);
-
-
-void pcre32_free_substring_list(PCRE_SPTR32 *stringptr);
-
-pcre32_jit_stack *pcre32_jit_stack_alloc(int startsize, int maxsize);
-
-
-void pcre32_jit_stack_free(pcre32_jit_stack *stack);
-
-
-void pcre32_assign_jit_stack(pcre32_extra *extra,
- pcre32_jit_callback callback, void *data);
-
-
-const unsigned char *pcre32_maketables(void);
-
-
-int pcre32_fullinfo(const pcre32 *code, const pcre32_extra *extra,
- int what, void *where);
-
-
-int pcre32_refcount(pcre32 *code, int adjust);
-
-
-int pcre32_config(int what, void *where);
-
-
-const char *pcre32_version(void);
-
-
-int pcre32_pattern_to_host_byte_order(pcre32 *code,
- pcre32_extra *extra, const unsigned char *tables);
-
-void *(*pcre32_malloc)(size_t);
-
-
-void (*pcre32_free)(void *);
-
-
-void *(*pcre32_stack_malloc)(size_t);
-
-
-void (*pcre32_stack_free)(void *);
-
-
-int (*pcre32_callout)(pcre32_callout_block *);
-
-int pcre32_utf32_to_host_byte_order(PCRE_UCHAR32 *output, - PCRE_SPTR32 input, int length, int *byte_order, - int keep_boms); -
--Starting with release 8.32, it is possible to compile a PCRE library that -supports 32-bit character strings, including UTF-32 strings, as well as or -instead of the original 8-bit library. This work was done by Christian Persch, -based on the work done by Zoltan Herczeg for the 16-bit library. All three -libraries contain identical sets of functions, used in exactly the same way. -Only the names of the functions and the data types of their arguments and -results are different. To avoid over-complication and reduce the documentation -maintenance load, most of the PCRE documentation describes the 8-bit library, -with only occasional references to the 16-bit and 32-bit libraries. This page -describes what is different when you use the 32-bit library. -
--WARNING: A single application can be linked with all or any of the three -libraries, but you must take care when processing any particular pattern -to use functions from just one library. For example, if you want to study -a pattern that was compiled with pcre32_compile(), you must do so -with pcre32_study(), not pcre_study(), and you must free the -study data with pcre32_free_study(). -
--There is only one header file, pcre.h. It contains prototypes for all the -functions in all libraries, as well as definitions of flags, structures, error -codes, etc. -
--In Unix-like systems, the 32-bit library is called libpcre32, and can -normally be accesss by adding -lpcre32 to the command for linking an -application that uses PCRE. -
--In the 8-bit library, strings are passed to PCRE library functions as vectors -of bytes with the C type "char *". In the 32-bit library, strings are passed as -vectors of unsigned 32-bit quantities. The macro PCRE_UCHAR32 specifies an -appropriate data type, and PCRE_SPTR32 is defined as "const PCRE_UCHAR32 *". In -very many environments, "unsigned int" is a 32-bit data type. When PCRE is -built, it defines PCRE_UCHAR32 as "unsigned int", but checks that it really is -a 32-bit data type. If it is not, the build fails with an error message telling -the maintainer to modify the definition appropriately. -
--The types of the opaque structures that are used for compiled 32-bit patterns -and JIT stacks are pcre32 and pcre32_jit_stack respectively. The -type of the user-accessible structure that is returned by pcre32_study() -is pcre32_extra, and the type of the structure that is used for passing -data to a callout function is pcre32_callout_block. These structures -contain the same fields, with the same names, as their 8-bit counterparts. The -only difference is that pointers to character strings are 32-bit instead of -8-bit types. -
--For every function in the 8-bit library there is a corresponding function in -the 32-bit library with a name that starts with pcre32_ instead of -pcre_. The prototypes are listed above. In addition, there is one extra -function, pcre32_utf32_to_host_byte_order(). This is a utility function -that converts a UTF-32 character string to host byte order if necessary. The -other 32-bit functions expect the strings they are passed to be in host byte -order. -
--The input and output arguments of -pcre32_utf32_to_host_byte_order() may point to the same address, that is, -conversion in place is supported. The output buffer must be at least as long as -the input. -
--The length argument specifies the number of 32-bit data units in the -input string; a negative value specifies a zero-terminated string. -
--If byte_order is NULL, it is assumed that the string starts off in host -byte order. This may be changed by byte-order marks (BOMs) anywhere in the -string (commonly as the first character). -
--If byte_order is not NULL, a non-zero value of the integer to which it -points means that the input starts off in host byte order, otherwise the -opposite order is assumed. Again, BOMs in the string can change this. The final -byte order is passed back at the end of processing. -
--If keep_boms is not zero, byte-order mark characters (0xfeff) are copied -into the output string. Otherwise they are discarded. -
--The result of the function is the number of 32-bit units placed into the output -buffer, including the zero terminator if the string was zero-terminated. -
--The lengths and starting offsets of subject strings must be specified in 32-bit -data units, and the offsets within subject strings that are returned by the -matching functions are in also 32-bit units rather than bytes. -
--The name-to-number translation table that is maintained for named subpatterns -uses 32-bit characters. The pcre32_get_stringtable_entries() function -returns the length of each entry in the table as the number of 32-bit data -units. -
--There are two new general option names, PCRE_UTF32 and PCRE_NO_UTF32_CHECK, -which correspond to PCRE_UTF8 and PCRE_NO_UTF8_CHECK in the 8-bit library. In -fact, these new options define the same bits in the options word. There is a -discussion about the -validity of UTF-32 strings -in the -pcreunicode -page. -
--For the pcre32_config() function there is an option PCRE_CONFIG_UTF32 -that returns 1 if UTF-32 support is configured, otherwise 0. If this option is -given to pcre_config() or pcre16_config(), or if the -PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF16 option is given to pcre32_config(), -the result is the PCRE_ERROR_BADOPTION error. -
--In 32-bit mode, when PCRE_UTF32 is not set, character values are treated in the -same way as in 8-bit, non UTF-8 mode, except, of course, that they can range -from 0 to 0x7fffffff instead of 0 to 0xff. Character types for characters less -than 0xff can therefore be influenced by the locale in the same way as before. -Characters greater than 0xff have only one case, and no "type" (such as letter -or digit). -
--In UTF-32 mode, the character code is Unicode, in the range 0 to 0x10ffff, with -the exception of values in the range 0xd800 to 0xdfff because those are -"surrogate" values that are ill-formed in UTF-32. -
--A UTF-32 string can indicate its endianness by special code knows as a -byte-order mark (BOM). The PCRE functions do not handle this, expecting strings -to be in host byte order. A utility function called -pcre32_utf32_to_host_byte_order() is provided to help with this (see -above). -
--The error PCRE_ERROR_BADUTF32 corresponds to its 8-bit counterpart. -The error PCRE_ERROR_BADMODE is given when a compiled -pattern is passed to a function that processes patterns in the other -mode, for example, if a pattern compiled with pcre_compile() is passed to -pcre32_exec(). -
--There are new error codes whose names begin with PCRE_UTF32_ERR for invalid -UTF-32 strings, corresponding to the PCRE_UTF8_ERR codes for UTF-8 strings that -are described in the section entitled -"Reason codes for invalid UTF-8 strings" -in the main -pcreapi -page. The UTF-32 errors are: -
- PCRE_UTF32_ERR1 Surrogate character (range from 0xd800 to 0xdfff) - PCRE_UTF32_ERR2 Non-character - PCRE_UTF32_ERR3 Character > 0x10ffff -- -
-If there is an error while compiling a pattern, the error text that is passed -back by pcre32_compile() or pcre32_compile2() is still an 8-bit -character string, zero-terminated. -
--The subject and mark fields in the callout block that is passed to -a callout function point to 32-bit vectors. -
--The pcretest program continues to operate with 8-bit input and output -files, but it can be used for testing the 32-bit library. If it is run with the -command line option -32, patterns and subject strings are converted from -8-bit to 32-bit before being passed to PCRE, and the 32-bit library functions -are used instead of the 8-bit ones. Returned 32-bit strings are converted to -8-bit for output. If both the 8-bit and the 16-bit libraries were not compiled, -pcretest defaults to 32-bit and the -32 option is ignored. -
--When PCRE is being built, the RunTest script that is called by "make -check" uses the pcretest -C option to discover which of the 8-bit, -16-bit and 32-bit libraries has been built, and runs the tests appropriately. -
--Not all the features of the 8-bit library are available with the 32-bit -library. The C++ and POSIX wrapper functions support only the 8-bit library, -and the pcregrep program is at present 8-bit only. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 May 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_assign_jit_stack.html b/libs/Pcre16/docs/doc/html/pcre_assign_jit_stack.html deleted file mode 100644 index b2eef704db..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_assign_jit_stack.html +++ /dev/null @@ -1,76 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-void pcre_assign_jit_stack(pcre_extra *extra,
- pcre_jit_callback callback, void *data);
-
-
-void pcre16_assign_jit_stack(pcre16_extra *extra,
- pcre16_jit_callback callback, void *data);
-
-
-void pcre32_assign_jit_stack(pcre32_extra *extra,
- pcre32_jit_callback callback, void *data);
-
-This function provides control over the memory used as a stack at run-time by a -call to pcre[16|32]_exec() with a pattern that has been successfully -compiled with JIT optimization. The arguments are: -
- extra the data pointer returned by pcre[16|32]_study() - callback a callback function - data a JIT stack or a value to be passed to the callback - function -- -
-If callback is NULL and data is NULL, an internal 32K block on -the machine stack is used. -
--If callback is NULL and data is not NULL, data must -be a valid JIT stack, the result of calling pcre[16|32]_jit_stack_alloc(). -
--If callback not NULL, it is called with data as an argument at -the start of matching, in order to set up a JIT stack. If the result is NULL, -the internal 32K stack is used; otherwise the return value must be a valid JIT -stack, the result of calling pcre[16|32]_jit_stack_alloc(). -
--You may safely assign the same JIT stack to multiple patterns, as long as they -are all matched in the same thread. In a multithread application, each thread -must use its own JIT stack. For more details, see the -pcrejit -page. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_compile.html b/libs/Pcre16/docs/doc/html/pcre_compile.html deleted file mode 100644 index 95b4bec63c..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_compile.html +++ /dev/null @@ -1,111 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-pcre *pcre_compile(const char *pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre16 *pcre16_compile(PCRE_SPTR16 pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre32 *pcre32_compile(PCRE_SPTR32 pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-This function compiles a regular expression into an internal form. It is the -same as pcre[16|32]_compile2(), except for the absence of the -errorcodeptr argument. Its arguments are: -
- pattern A zero-terminated string containing the - regular expression to be compiled - options Zero or more option bits - errptr Where to put an error message - erroffset Offset in pattern where error was found - tableptr Pointer to character tables, or NULL to - use the built-in default --The option bits are: -
- PCRE_ANCHORED Force pattern anchoring - PCRE_AUTO_CALLOUT Compile automatic callouts - PCRE_BSR_ANYCRLF \R matches only CR, LF, or CRLF - PCRE_BSR_UNICODE \R matches all Unicode line endings - PCRE_CASELESS Do caseless matching - PCRE_DOLLAR_ENDONLY $ not to match newline at end - PCRE_DOTALL . matches anything including NL - PCRE_DUPNAMES Allow duplicate names for subpatterns - PCRE_EXTENDED Ignore white space and # comments - PCRE_EXTRA PCRE extra features - (not much use currently) - PCRE_FIRSTLINE Force matching to be before newline - PCRE_JAVASCRIPT_COMPAT JavaScript compatibility - PCRE_MULTILINE ^ and $ match newlines within data - PCRE_NEVER_UTF Lock out UTF, e.g. via (*UTF) - PCRE_NEWLINE_ANY Recognize any Unicode newline sequence - PCRE_NEWLINE_ANYCRLF Recognize CR, LF, and CRLF as newline - sequences - PCRE_NEWLINE_CR Set CR as the newline sequence - PCRE_NEWLINE_CRLF Set CRLF as the newline sequence - PCRE_NEWLINE_LF Set LF as the newline sequence - PCRE_NO_AUTO_CAPTURE Disable numbered capturing paren- - theses (named ones available) - PCRE_NO_AUTO_POSSESS Disable auto-possessification - PCRE_NO_START_OPTIMIZE Disable match-time start optimizations - PCRE_NO_UTF16_CHECK Do not check the pattern for UTF-16 - validity (only relevant if - PCRE_UTF16 is set) - PCRE_NO_UTF32_CHECK Do not check the pattern for UTF-32 - validity (only relevant if - PCRE_UTF32 is set) - PCRE_NO_UTF8_CHECK Do not check the pattern for UTF-8 - validity (only relevant if - PCRE_UTF8 is set) - PCRE_UCP Use Unicode properties for \d, \w, etc. - PCRE_UNGREEDY Invert greediness of quantifiers - PCRE_UTF16 Run in pcre16_compile() UTF-16 mode - PCRE_UTF32 Run in pcre32_compile() UTF-32 mode - PCRE_UTF8 Run in pcre_compile() UTF-8 mode --PCRE must be built with UTF support in order to use PCRE_UTF8/16/32 and -PCRE_NO_UTF8/16/32_CHECK, and with UCP support if PCRE_UCP is used. - -
-The yield of the function is a pointer to a private data structure that -contains the compiled pattern, or NULL if an error was detected. Note that -compiling regular expressions with one version of PCRE for use with a different -version is not guaranteed to work and may cause crashes. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_compile2.html b/libs/Pcre16/docs/doc/html/pcre_compile2.html deleted file mode 100644 index 9cd56a237b..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_compile2.html +++ /dev/null @@ -1,115 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-pcre *pcre_compile2(const char *pattern, int options,
- int *errorcodeptr,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre16 *pcre16_compile2(PCRE_SPTR16 pattern, int options,
- int *errorcodeptr,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre32 *pcre32_compile2(PCRE_SPTR32 pattern, int options,
-" int *errorcodeptr,£
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-This function compiles a regular expression into an internal form. It is the -same as pcre[16|32]_compile(), except for the addition of the -errorcodeptr argument. The arguments are: -
- pattern A zero-terminated string containing the - regular expression to be compiled - options Zero or more option bits - errorcodeptr Where to put an error code - errptr Where to put an error message - erroffset Offset in pattern where error was found - tableptr Pointer to character tables, or NULL to - use the built-in default --The option bits are: -
- PCRE_ANCHORED Force pattern anchoring - PCRE_AUTO_CALLOUT Compile automatic callouts - PCRE_BSR_ANYCRLF \R matches only CR, LF, or CRLF - PCRE_BSR_UNICODE \R matches all Unicode line endings - PCRE_CASELESS Do caseless matching - PCRE_DOLLAR_ENDONLY $ not to match newline at end - PCRE_DOTALL . matches anything including NL - PCRE_DUPNAMES Allow duplicate names for subpatterns - PCRE_EXTENDED Ignore white space and # comments - PCRE_EXTRA PCRE extra features - (not much use currently) - PCRE_FIRSTLINE Force matching to be before newline - PCRE_JAVASCRIPT_COMPAT JavaScript compatibility - PCRE_MULTILINE ^ and $ match newlines within data - PCRE_NEVER_UTF Lock out UTF, e.g. via (*UTF) - PCRE_NEWLINE_ANY Recognize any Unicode newline sequence - PCRE_NEWLINE_ANYCRLF Recognize CR, LF, and CRLF as newline - sequences - PCRE_NEWLINE_CR Set CR as the newline sequence - PCRE_NEWLINE_CRLF Set CRLF as the newline sequence - PCRE_NEWLINE_LF Set LF as the newline sequence - PCRE_NO_AUTO_CAPTURE Disable numbered capturing paren- - theses (named ones available) - PCRE_NO_AUTO_POSSESS Disable auto-possessification - PCRE_NO_START_OPTIMIZE Disable match-time start optimizations - PCRE_NO_UTF16_CHECK Do not check the pattern for UTF-16 - validity (only relevant if - PCRE_UTF16 is set) - PCRE_NO_UTF32_CHECK Do not check the pattern for UTF-32 - validity (only relevant if - PCRE_UTF32 is set) - PCRE_NO_UTF8_CHECK Do not check the pattern for UTF-8 - validity (only relevant if - PCRE_UTF8 is set) - PCRE_UCP Use Unicode properties for \d, \w, etc. - PCRE_UNGREEDY Invert greediness of quantifiers - PCRE_UTF16 Run pcre16_compile() in UTF-16 mode - PCRE_UTF32 Run pcre32_compile() in UTF-32 mode - PCRE_UTF8 Run pcre_compile() in UTF-8 mode --PCRE must be built with UTF support in order to use PCRE_UTF8/16/32 and -PCRE_NO_UTF8/16/32_CHECK, and with UCP support if PCRE_UCP is used. - -
-The yield of the function is a pointer to a private data structure that -contains the compiled pattern, or NULL if an error was detected. Note that -compiling regular expressions with one version of PCRE for use with a different -version is not guaranteed to work and may cause crashes. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_config.html b/libs/Pcre16/docs/doc/html/pcre_config.html deleted file mode 100644 index 72fb9caa1f..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_config.html +++ /dev/null @@ -1,94 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--int pcre_config(int what, void *where); -
--int pcre16_config(int what, void *where); -
--int pcre32_config(int what, void *where); -
--This function makes it possible for a client program to find out which optional -features are available in the version of the PCRE library it is using. The -arguments are as follows: -
- what A code specifying what information is required - where Points to where to put the data --The where argument must point to an integer variable, except for -PCRE_CONFIG_MATCH_LIMIT, PCRE_CONFIG_MATCH_LIMIT_RECURSION, and -PCRE_CONFIG_PARENS_LIMIT, when it must point to an unsigned long integer, -and for PCRE_CONFIG_JITTARGET, when it must point to a const char*. -The available codes are: -
- PCRE_CONFIG_JIT Availability of just-in-time compiler - support (1=yes 0=no) - PCRE_CONFIG_JITTARGET String containing information about the - target architecture for the JIT compiler, - or NULL if there is no JIT support - PCRE_CONFIG_LINK_SIZE Internal link size: 2, 3, or 4 - PCRE_CONFIG_PARENS_LIMIT Parentheses nesting limit - PCRE_CONFIG_MATCH_LIMIT Internal resource limit - PCRE_CONFIG_MATCH_LIMIT_RECURSION - Internal recursion depth limit - PCRE_CONFIG_NEWLINE Value of the default newline sequence: - 13 (0x000d) for CR - 10 (0x000a) for LF - 3338 (0x0d0a) for CRLF - -2 for ANYCRLF - -1 for ANY - PCRE_CONFIG_BSR Indicates what \R matches by default: - 0 all Unicode line endings - 1 CR, LF, or CRLF only - PCRE_CONFIG_POSIX_MALLOC_THRESHOLD - Threshold of return slots, above which - malloc() is used by the POSIX API - PCRE_CONFIG_STACKRECURSE Recursion implementation (1=stack 0=heap) - PCRE_CONFIG_UTF16 Availability of UTF-16 support (1=yes - 0=no); option for pcre16_config() - PCRE_CONFIG_UTF32 Availability of UTF-32 support (1=yes - 0=no); option for pcre32_config() - PCRE_CONFIG_UTF8 Availability of UTF-8 support (1=yes 0=no); - option for pcre_config() - PCRE_CONFIG_UNICODE_PROPERTIES - Availability of Unicode property support - (1=yes 0=no) --The function yields 0 on success or PCRE_ERROR_BADOPTION otherwise. That error -is also given if PCRE_CONFIG_UTF16 or PCRE_CONFIG_UTF32 is passed to -pcre_config(), if PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF32 is passed to -pcre16_config(), or if PCRE_CONFIG_UTF8 or PCRE_CONFIG_UTF16 is passed to -pcre32_config(). - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_copy_named_substring.html b/libs/Pcre16/docs/doc/html/pcre_copy_named_substring.html deleted file mode 100644 index 77b48043cd..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_copy_named_substring.html +++ /dev/null @@ -1,65 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_copy_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- char *buffer, int buffersize);
-
-
-int pcre16_copy_named_substring(const pcre16 *code,
- PCRE_SPTR16 subject, int *ovector,
- int stringcount, PCRE_SPTR16 stringname,
- PCRE_UCHAR16 *buffer, int buffersize);
-
-
-int pcre32_copy_named_substring(const pcre32 *code,
- PCRE_SPTR32 subject, int *ovector,
- int stringcount, PCRE_SPTR32 stringname,
- PCRE_UCHAR32 *buffer, int buffersize);
-
-This is a convenience function for extracting a captured substring, identified -by name, into a given buffer. The arguments are: -
- code Pattern that was successfully matched - subject Subject that has been successfully matched - ovector Offset vector that pcre[16|32]_exec() used - stringcount Value returned by pcre[16|32]_exec() - stringname Name of the required substring - buffer Buffer to receive the string - buffersize Size of buffer --The yield is the length of the substring, PCRE_ERROR_NOMEMORY if the buffer was -too small, or PCRE_ERROR_NOSUBSTRING if the string name is invalid. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_copy_substring.html b/libs/Pcre16/docs/doc/html/pcre_copy_substring.html deleted file mode 100644 index ecaebe8533..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_copy_substring.html +++ /dev/null @@ -1,61 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_copy_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber, char *buffer,
- int buffersize);
-
-
-int pcre16_copy_substring(PCRE_SPTR16 subject, int *ovector,
- int stringcount, int stringnumber, PCRE_UCHAR16 *buffer,
- int buffersize);
-
-
-int pcre32_copy_substring(PCRE_SPTR32 subject, int *ovector,
- int stringcount, int stringnumber, PCRE_UCHAR32 *buffer,
- int buffersize);
-
-This is a convenience function for extracting a captured substring into a given -buffer. The arguments are: -
- subject Subject that has been successfully matched - ovector Offset vector that pcre[16|32]_exec() used - stringcount Value returned by pcre[16|32]_exec() - stringnumber Number of the required substring - buffer Buffer to receive the string - buffersize Size of buffer --The yield is the length of the string, PCRE_ERROR_NOMEMORY if the buffer was -too small, or PCRE_ERROR_NOSUBSTRING if the string number is invalid. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_dfa_exec.html b/libs/Pcre16/docs/doc/html/pcre_dfa_exec.html deleted file mode 100644 index 5fff6a7e0a..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_dfa_exec.html +++ /dev/null @@ -1,129 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-
-int pcre16_dfa_exec(const pcre16 *code, const pcre16_extra *extra,
- PCRE_SPTR16 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-
-int pcre32_dfa_exec(const pcre32 *code, const pcre32_extra *extra,
- PCRE_SPTR32 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-This function matches a compiled regular expression against a given subject -string, using an alternative matching algorithm that scans the subject string -just once (not Perl-compatible). Note that the main, Perl-compatible, -matching function is pcre[16|32]_exec(). The arguments for this function -are: -
- code Points to the compiled pattern - extra Points to an associated pcre[16|32]_extra structure, - or is NULL - subject Points to the subject string - length Length of the subject string - startoffset Offset in the subject at which to start matching - options Option bits - ovector Points to a vector of ints for result offsets - ovecsize Number of elements in the vector - workspace Points to a vector of ints used as working space - wscount Number of elements in the vector --The units for length and startoffset are bytes for -pcre_exec(), 16-bit data items for pcre16_exec(), and 32-bit items -for pcre32_exec(). The options are: -
- PCRE_ANCHORED Match only at the first position - PCRE_BSR_ANYCRLF \R matches only CR, LF, or CRLF - PCRE_BSR_UNICODE \R matches all Unicode line endings - PCRE_NEWLINE_ANY Recognize any Unicode newline sequence - PCRE_NEWLINE_ANYCRLF Recognize CR, LF, & CRLF as newline sequences - PCRE_NEWLINE_CR Recognize CR as the only newline sequence - PCRE_NEWLINE_CRLF Recognize CRLF as the only newline sequence - PCRE_NEWLINE_LF Recognize LF as the only newline sequence - PCRE_NOTBOL Subject is not the beginning of a line - PCRE_NOTEOL Subject is not the end of a line - PCRE_NOTEMPTY An empty string is not a valid match - PCRE_NOTEMPTY_ATSTART An empty string at the start of the subject - is not a valid match - PCRE_NO_START_OPTIMIZE Do not do "start-match" optimizations - PCRE_NO_UTF16_CHECK Do not check the subject for UTF-16 - validity (only relevant if PCRE_UTF16 - was set at compile time) - PCRE_NO_UTF32_CHECK Do not check the subject for UTF-32 - validity (only relevant if PCRE_UTF32 - was set at compile time) - PCRE_NO_UTF8_CHECK Do not check the subject for UTF-8 - validity (only relevant if PCRE_UTF8 - was set at compile time) - PCRE_PARTIAL ) Return PCRE_ERROR_PARTIAL for a partial - PCRE_PARTIAL_SOFT ) match if no full matches are found - PCRE_PARTIAL_HARD Return PCRE_ERROR_PARTIAL for a partial match - even if there is a full match as well - PCRE_DFA_SHORTEST Return only the shortest match - PCRE_DFA_RESTART Restart after a partial match --There are restrictions on what may appear in a pattern when using this matching -function. Details are given in the -pcrematching -documentation. For details of partial matching, see the -pcrepartial -page. - -
-A pcre[16|32]_extra structure contains the following fields: -
- flags Bits indicating which fields are set - study_data Opaque data from pcre[16|32]_study() - match_limit Limit on internal resource use - match_limit_recursion Limit on internal recursion depth - callout_data Opaque data passed back to callouts - tables Points to character tables or is NULL - mark For passing back a *MARK pointer - executable_jit Opaque data from JIT compilation --The flag bits are PCRE_EXTRA_STUDY_DATA, PCRE_EXTRA_MATCH_LIMIT, -PCRE_EXTRA_MATCH_LIMIT_RECURSION, PCRE_EXTRA_CALLOUT_DATA, -PCRE_EXTRA_TABLES, PCRE_EXTRA_MARK and PCRE_EXTRA_EXECUTABLE_JIT. For this -matching function, the match_limit and match_limit_recursion fields -are not used, and must not be set. The PCRE_EXTRA_EXECUTABLE_JIT flag and -the corresponding variable are ignored. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_exec.html b/libs/Pcre16/docs/doc/html/pcre_exec.html deleted file mode 100644 index 18e1a13ff8..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_exec.html +++ /dev/null @@ -1,111 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-
-int pcre16_exec(const pcre16 *code, const pcre16_extra *extra,
- PCRE_SPTR16 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-
-int pcre32_exec(const pcre32 *code, const pcre32_extra *extra,
- PCRE_SPTR32 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-This function matches a compiled regular expression against a given subject -string, using a matching algorithm that is similar to Perl's. It returns -offsets to captured substrings. Its arguments are: -
- code Points to the compiled pattern - extra Points to an associated pcre[16|32]_extra structure, - or is NULL - subject Points to the subject string - length Length of the subject string - startoffset Offset in the subject at which to start matching - options Option bits - ovector Points to a vector of ints for result offsets - ovecsize Number of elements in the vector (a multiple of 3) --The units for length and startoffset are bytes for -pcre_exec(), 16-bit data items for pcre16_exec(), and 32-bit items -for pcre32_exec(). The options are: -
- PCRE_ANCHORED Match only at the first position - PCRE_BSR_ANYCRLF \R matches only CR, LF, or CRLF - PCRE_BSR_UNICODE \R matches all Unicode line endings - PCRE_NEWLINE_ANY Recognize any Unicode newline sequence - PCRE_NEWLINE_ANYCRLF Recognize CR, LF, & CRLF as newline sequences - PCRE_NEWLINE_CR Recognize CR as the only newline sequence - PCRE_NEWLINE_CRLF Recognize CRLF as the only newline sequence - PCRE_NEWLINE_LF Recognize LF as the only newline sequence - PCRE_NOTBOL Subject string is not the beginning of a line - PCRE_NOTEOL Subject string is not the end of a line - PCRE_NOTEMPTY An empty string is not a valid match - PCRE_NOTEMPTY_ATSTART An empty string at the start of the subject - is not a valid match - PCRE_NO_START_OPTIMIZE Do not do "start-match" optimizations - PCRE_NO_UTF16_CHECK Do not check the subject for UTF-16 - validity (only relevant if PCRE_UTF16 - was set at compile time) - PCRE_NO_UTF32_CHECK Do not check the subject for UTF-32 - validity (only relevant if PCRE_UTF32 - was set at compile time) - PCRE_NO_UTF8_CHECK Do not check the subject for UTF-8 - validity (only relevant if PCRE_UTF8 - was set at compile time) - PCRE_PARTIAL ) Return PCRE_ERROR_PARTIAL for a partial - PCRE_PARTIAL_SOFT ) match if no full matches are found - PCRE_PARTIAL_HARD Return PCRE_ERROR_PARTIAL for a partial match - if that is found before a full match --For details of partial matching, see the -pcrepartial -page. A pcre_extra structure contains the following fields: -
- flags Bits indicating which fields are set - study_data Opaque data from pcre[16|32]_study() - match_limit Limit on internal resource use - match_limit_recursion Limit on internal recursion depth - callout_data Opaque data passed back to callouts - tables Points to character tables or is NULL - mark For passing back a *MARK pointer - executable_jit Opaque data from JIT compilation --The flag bits are PCRE_EXTRA_STUDY_DATA, PCRE_EXTRA_MATCH_LIMIT, -PCRE_EXTRA_MATCH_LIMIT_RECURSION, PCRE_EXTRA_CALLOUT_DATA, -PCRE_EXTRA_TABLES, PCRE_EXTRA_MARK and PCRE_EXTRA_EXECUTABLE_JIT. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_free_study.html b/libs/Pcre16/docs/doc/html/pcre_free_study.html deleted file mode 100644 index 7f9e10e863..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_free_study.html +++ /dev/null @@ -1,46 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--void pcre_free_study(pcre_extra *extra); -
--void pcre16_free_study(pcre16_extra *extra); -
--void pcre32_free_study(pcre32_extra *extra); -
--This function is used to free the memory used for the data generated by a call -to pcre[16|32]_study() when it is no longer needed. The argument must be the -result of such a call. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_free_substring.html b/libs/Pcre16/docs/doc/html/pcre_free_substring.html deleted file mode 100644 index 1fe6610746..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_free_substring.html +++ /dev/null @@ -1,46 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--void pcre_free_substring(const char *stringptr); -
--void pcre16_free_substring(PCRE_SPTR16 stringptr); -
--void pcre32_free_substring(PCRE_SPTR32 stringptr); -
--This is a convenience function for freeing the store obtained by a previous -call to pcre[16|32]_get_substring() or pcre[16|32]_get_named_substring(). -Its only argument is a pointer to the string. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_free_substring_list.html b/libs/Pcre16/docs/doc/html/pcre_free_substring_list.html deleted file mode 100644 index c0861780b4..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_free_substring_list.html +++ /dev/null @@ -1,46 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--void pcre_free_substring_list(const char **stringptr); -
--void pcre16_free_substring_list(PCRE_SPTR16 *stringptr); -
--void pcre32_free_substring_list(PCRE_SPTR32 *stringptr); -
--This is a convenience function for freeing the store obtained by a previous -call to pcre[16|32]_get_substring_list(). Its only argument is a pointer to -the list of string pointers. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_fullinfo.html b/libs/Pcre16/docs/doc/html/pcre_fullinfo.html deleted file mode 100644 index 2b7c72b3b9..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_fullinfo.html +++ /dev/null @@ -1,118 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
- int what, void *where);
-
-
-int pcre16_fullinfo(const pcre16 *code, const pcre16_extra *extra,
- int what, void *where);
-
-
-int pcre32_fullinfo(const pcre32 *code, const pcre32_extra *extra,
- int what, void *where);
-
-This function returns information about a compiled pattern. Its arguments are: -
- code Compiled regular expression - extra Result of pcre[16|32]_study() or NULL - what What information is required - where Where to put the information --The following information is available: -
- PCRE_INFO_BACKREFMAX Number of highest back reference - PCRE_INFO_CAPTURECOUNT Number of capturing subpatterns - PCRE_INFO_DEFAULT_TABLES Pointer to default tables - PCRE_INFO_FIRSTBYTE Fixed first data unit for a match, or - -1 for start of string - or after newline, or - -2 otherwise - PCRE_INFO_FIRSTTABLE Table of first data units (after studying) - PCRE_INFO_HASCRORLF Return 1 if explicit CR or LF matches exist - PCRE_INFO_JCHANGED Return 1 if (?J) or (?-J) was used - PCRE_INFO_JIT Return 1 after successful JIT compilation - PCRE_INFO_JITSIZE Size of JIT compiled code - PCRE_INFO_LASTLITERAL Literal last data unit required - PCRE_INFO_MINLENGTH Lower bound length of matching strings - PCRE_INFO_MATCHEMPTY Return 1 if the pattern can match an empty string, - 0 otherwise - PCRE_INFO_MATCHLIMIT Match limit if set, otherwise PCRE_RROR_UNSET - PCRE_INFO_MAXLOOKBEHIND Length (in characters) of the longest lookbehind assertion - PCRE_INFO_NAMECOUNT Number of named subpatterns - PCRE_INFO_NAMEENTRYSIZE Size of name table entry - PCRE_INFO_NAMETABLE Pointer to name table - PCRE_INFO_OKPARTIAL Return 1 if partial matching can be tried - (always returns 1 after release 8.00) - PCRE_INFO_OPTIONS Option bits used for compilation - PCRE_INFO_SIZE Size of compiled pattern - PCRE_INFO_STUDYSIZE Size of study data - PCRE_INFO_FIRSTCHARACTER Fixed first data unit for a match - PCRE_INFO_FIRSTCHARACTERFLAGS Returns - 1 if there is a first data character set, which can - then be retrieved using PCRE_INFO_FIRSTCHARACTER, - 2 if the first character is at the start of the data - string or after a newline, and - 0 otherwise - PCRE_INFO_RECURSIONLIMIT Recursion limit if set, otherwise PCRE_ERROR_UNSET - PCRE_INFO_REQUIREDCHAR Literal last data unit required - PCRE_INFO_REQUIREDCHARFLAGS Returns 1 if the last data character is set (which can then - be retrieved using PCRE_INFO_REQUIREDCHAR); 0 otherwise --The where argument must point to an integer variable, except for the -following what values: -
- PCRE_INFO_DEFAULT_TABLES const uint8_t * - PCRE_INFO_FIRSTCHARACTER uint32_t - PCRE_INFO_FIRSTTABLE const uint8_t * - PCRE_INFO_JITSIZE size_t - PCRE_INFO_MATCHLIMIT uint32_t - PCRE_INFO_NAMETABLE PCRE_SPTR16 (16-bit library) - PCRE_INFO_NAMETABLE PCRE_SPTR32 (32-bit library) - PCRE_INFO_NAMETABLE const unsigned char * (8-bit library) - PCRE_INFO_OPTIONS unsigned long int - PCRE_INFO_SIZE size_t - PCRE_INFO_STUDYSIZE size_t - PCRE_INFO_RECURSIONLIMIT uint32_t - PCRE_INFO_REQUIREDCHAR uint32_t --The yield of the function is zero on success or: -
- PCRE_ERROR_NULL the argument code was NULL - the argument where was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - PCRE_ERROR_BADOPTION the value of what was invalid - PCRE_ERROR_UNSET the option was not set -- -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_get_named_substring.html b/libs/Pcre16/docs/doc/html/pcre_get_named_substring.html deleted file mode 100644 index 72924d9b25..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_get_named_substring.html +++ /dev/null @@ -1,68 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_get_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- const char **stringptr);
-
-
-int pcre16_get_named_substring(const pcre16 *code,
- PCRE_SPTR16 subject, int *ovector,
- int stringcount, PCRE_SPTR16 stringname,
- PCRE_SPTR16 *stringptr);
-
-
-int pcre32_get_named_substring(const pcre32 *code,
- PCRE_SPTR32 subject, int *ovector,
- int stringcount, PCRE_SPTR32 stringname,
- PCRE_SPTR32 *stringptr);
-
-This is a convenience function for extracting a captured substring by name. The -arguments are: -
- code Compiled pattern - subject Subject that has been successfully matched - ovector Offset vector that pcre[16|32]_exec() used - stringcount Value returned by pcre[16|32]_exec() - stringname Name of the required substring - stringptr Where to put the string pointer --The memory in which the substring is placed is obtained by calling -pcre[16|32]_malloc(). The convenience function -pcre[16|32]_free_substring() can be used to free it when it is no longer -needed. The yield of the function is the length of the extracted substring, -PCRE_ERROR_NOMEMORY if sufficient memory could not be obtained, or -PCRE_ERROR_NOSUBSTRING if the string name is invalid. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_get_stringnumber.html b/libs/Pcre16/docs/doc/html/pcre_get_stringnumber.html deleted file mode 100644 index 7324d782e7..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_get_stringnumber.html +++ /dev/null @@ -1,57 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_get_stringnumber(const pcre *code,
- const char *name);
-
-
-int pcre16_get_stringnumber(const pcre16 *code,
- PCRE_SPTR16 name);
-
-
-int pcre32_get_stringnumber(const pcre32 *code,
- PCRE_SPTR32 name);
-
-This convenience function finds the number of a named substring capturing -parenthesis in a compiled pattern. Its arguments are: -
- code Compiled regular expression - name Name whose number is required --The yield of the function is the number of the parenthesis if the name is -found, or PCRE_ERROR_NOSUBSTRING otherwise. When duplicate names are allowed -(PCRE_DUPNAMES is set), it is not defined which of the numbers is returned by -pcre[16|32]_get_stringnumber(). You can obtain the complete list by calling -pcre[16|32]_get_stringtable_entries(). - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_get_stringtable_entries.html b/libs/Pcre16/docs/doc/html/pcre_get_stringtable_entries.html deleted file mode 100644 index 79906798e6..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_get_stringtable_entries.html +++ /dev/null @@ -1,60 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_get_stringtable_entries(const pcre *code,
- const char *name, char **first, char **last);
-
-
-int pcre16_get_stringtable_entries(const pcre16 *code,
- PCRE_SPTR16 name, PCRE_UCHAR16 **first, PCRE_UCHAR16 **last);
-
-
-int pcre32_get_stringtable_entries(const pcre32 *code,
- PCRE_SPTR32 name, PCRE_UCHAR32 **first, PCRE_UCHAR32 **last);
-
-This convenience function finds, for a compiled pattern, the first and last -entries for a given name in the table that translates capturing parenthesis -names into numbers. When names are required to be unique (PCRE_DUPNAMES is -not set), it is usually easier to use pcre[16|32]_get_stringnumber() -instead. -
- code Compiled regular expression - name Name whose entries required - first Where to return a pointer to the first entry - last Where to return a pointer to the last entry --The yield of the function is the length of each entry, or -PCRE_ERROR_NOSUBSTRING if none are found. - -
-There is a complete description of the PCRE native API, including the format of -the table entries, in the -pcreapi -page, and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_get_substring.html b/libs/Pcre16/docs/doc/html/pcre_get_substring.html deleted file mode 100644 index 1a8e4f5a49..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_get_substring.html +++ /dev/null @@ -1,64 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_get_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber,
- const char **stringptr);
-
-
-int pcre16_get_substring(PCRE_SPTR16 subject, int *ovector,
- int stringcount, int stringnumber,
- PCRE_SPTR16 *stringptr);
-
-
-int pcre32_get_substring(PCRE_SPTR32 subject, int *ovector,
- int stringcount, int stringnumber,
- PCRE_SPTR32 *stringptr);
-
-This is a convenience function for extracting a captured substring. The -arguments are: -
- subject Subject that has been successfully matched - ovector Offset vector that pcre[16|32]_exec() used - stringcount Value returned by pcre[16|32]_exec() - stringnumber Number of the required substring - stringptr Where to put the string pointer --The memory in which the substring is placed is obtained by calling -pcre[16|32]_malloc(). The convenience function -pcre[16|32]_free_substring() can be used to free it when it is no longer -needed. The yield of the function is the length of the substring, -PCRE_ERROR_NOMEMORY if sufficient memory could not be obtained, or -PCRE_ERROR_NOSUBSTRING if the string number is invalid. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_get_substring_list.html b/libs/Pcre16/docs/doc/html/pcre_get_substring_list.html deleted file mode 100644 index 7e8c6bc858..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_get_substring_list.html +++ /dev/null @@ -1,61 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_get_substring_list(const char *subject,
- int *ovector, int stringcount, const char ***listptr);
-
-
-int pcre16_get_substring_list(PCRE_SPTR16 subject,
- int *ovector, int stringcount, PCRE_SPTR16 **listptr);
-
-
-int pcre32_get_substring_list(PCRE_SPTR32 subject,
- int *ovector, int stringcount, PCRE_SPTR32 **listptr);
-
-This is a convenience function for extracting a list of all the captured -substrings. The arguments are: -
- subject Subject that has been successfully matched - ovector Offset vector that pcre[16|32]_exec used - stringcount Value returned by pcre[16|32]_exec - listptr Where to put a pointer to the list --The memory in which the substrings and the list are placed is obtained by -calling pcre[16|32]_malloc(). The convenience function -pcre[16|32]_free_substring_list() can be used to free it when it is no -longer needed. A pointer to a list of pointers is put in the variable whose -address is in listptr. The list is terminated by a NULL pointer. The -yield of the function is zero on success or PCRE_ERROR_NOMEMORY if sufficient -memory could not be obtained. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_jit_exec.html b/libs/Pcre16/docs/doc/html/pcre_jit_exec.html deleted file mode 100644 index 4ebb0cbcac..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_jit_exec.html +++ /dev/null @@ -1,108 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_jit_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- pcre_jit_stack *jstack);
-
-
-int pcre16_jit_exec(const pcre16 *code, const pcre16_extra *extra,
- PCRE_SPTR16 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- pcre_jit_stack *jstack);
-
-
-int pcre32_jit_exec(const pcre32 *code, const pcre32_extra *extra,
- PCRE_SPTR32 subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- pcre_jit_stack *jstack);
-
-This function matches a compiled regular expression that has been successfully -studied with one of the JIT options against a given subject string, using a -matching algorithm that is similar to Perl's. It is a "fast path" interface to -JIT, and it bypasses some of the sanity checks that pcre_exec() applies. -It returns offsets to captured substrings. Its arguments are: -
- code Points to the compiled pattern - extra Points to an associated pcre[16|32]_extra structure, - or is NULL - subject Points to the subject string - length Length of the subject string, in bytes - startoffset Offset in bytes in the subject at which to - start matching - options Option bits - ovector Points to a vector of ints for result offsets - ovecsize Number of elements in the vector (a multiple of 3) - jstack Pointer to a JIT stack --The allowed options are: -
- PCRE_NOTBOL Subject string is not the beginning of a line - PCRE_NOTEOL Subject string is not the end of a line - PCRE_NOTEMPTY An empty string is not a valid match - PCRE_NOTEMPTY_ATSTART An empty string at the start of the subject - is not a valid match - PCRE_NO_UTF16_CHECK Do not check the subject for UTF-16 - validity (only relevant if PCRE_UTF16 - was set at compile time) - PCRE_NO_UTF32_CHECK Do not check the subject for UTF-32 - validity (only relevant if PCRE_UTF32 - was set at compile time) - PCRE_NO_UTF8_CHECK Do not check the subject for UTF-8 - validity (only relevant if PCRE_UTF8 - was set at compile time) - PCRE_PARTIAL ) Return PCRE_ERROR_PARTIAL for a partial - PCRE_PARTIAL_SOFT ) match if no full matches are found - PCRE_PARTIAL_HARD Return PCRE_ERROR_PARTIAL for a partial match - if that is found before a full match --However, the PCRE_NO_UTF[8|16|32]_CHECK options have no effect, as this check -is never applied. For details of partial matching, see the -pcrepartial -page. A pcre_extra structure contains the following fields: -
- flags Bits indicating which fields are set - study_data Opaque data from pcre[16|32]_study() - match_limit Limit on internal resource use - match_limit_recursion Limit on internal recursion depth - callout_data Opaque data passed back to callouts - tables Points to character tables or is NULL - mark For passing back a *MARK pointer - executable_jit Opaque data from JIT compilation --The flag bits are PCRE_EXTRA_STUDY_DATA, PCRE_EXTRA_MATCH_LIMIT, -PCRE_EXTRA_MATCH_LIMIT_RECURSION, PCRE_EXTRA_CALLOUT_DATA, -PCRE_EXTRA_TABLES, PCRE_EXTRA_MARK and PCRE_EXTRA_EXECUTABLE_JIT. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the JIT API in the -pcrejit -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_jit_stack_alloc.html b/libs/Pcre16/docs/doc/html/pcre_jit_stack_alloc.html deleted file mode 100644 index 23ba450750..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_jit_stack_alloc.html +++ /dev/null @@ -1,55 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-pcre_jit_stack *pcre_jit_stack_alloc(int startsize,
- int maxsize);
-
-
-pcre16_jit_stack *pcre16_jit_stack_alloc(int startsize,
- int maxsize);
-
-
-pcre32_jit_stack *pcre32_jit_stack_alloc(int startsize,
- int maxsize);
-
-This function is used to create a stack for use by the code compiled by the JIT -optimization of pcre[16|32]_study(). The arguments are a starting size for -the stack, and a maximum size to which it is allowed to grow. The result can be -passed to the JIT run-time code by pcre[16|32]_assign_jit_stack(), or that -function can set up a callback for obtaining a stack. A maximum stack size of -512K to 1M should be more than enough for any pattern. For more details, see -the -pcrejit -page. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_jit_stack_free.html b/libs/Pcre16/docs/doc/html/pcre_jit_stack_free.html deleted file mode 100644 index 8bd06e4655..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_jit_stack_free.html +++ /dev/null @@ -1,48 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--void pcre_jit_stack_free(pcre_jit_stack *stack); -
--void pcre16_jit_stack_free(pcre16_jit_stack *stack); -
--void pcre32_jit_stack_free(pcre32_jit_stack *stack); -
--This function is used to free a JIT stack that was created by -pcre[16|32]_jit_stack_alloc() when it is no longer needed. For more details, -see the -pcrejit -page. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_maketables.html b/libs/Pcre16/docs/doc/html/pcre_maketables.html deleted file mode 100644 index 3a7b5ebc4a..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_maketables.html +++ /dev/null @@ -1,48 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--const unsigned char *pcre_maketables(void); -
--const unsigned char *pcre16_maketables(void); -
--const unsigned char *pcre32_maketables(void); -
--This function builds a set of character tables for character values less than -256. These can be passed to pcre[16|32]_compile() to override PCRE's -internal, built-in tables (which were made by pcre[16|32]_maketables() when -PCRE was compiled). You might want to do this if you are using a non-standard -locale. The function yields a pointer to the tables. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_pattern_to_host_byte_order.html b/libs/Pcre16/docs/doc/html/pcre_pattern_to_host_byte_order.html deleted file mode 100644 index 1b1c80372b..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_pattern_to_host_byte_order.html +++ /dev/null @@ -1,58 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-int pcre_pattern_to_host_byte_order(pcre *code,
- pcre_extra *extra, const unsigned char *tables);
-
-
-int pcre16_pattern_to_host_byte_order(pcre16 *code,
- pcre16_extra *extra, const unsigned char *tables);
-
-
-int pcre32_pattern_to_host_byte_order(pcre32 *code,
- pcre32_extra *extra, const unsigned char *tables);
-
-This function ensures that the bytes in 2-byte and 4-byte values in a compiled -pattern are in the correct order for the current host. It is useful when a -pattern that has been compiled on one host is transferred to another that might -have different endianness. The arguments are: -
- code A compiled regular expression - extra Points to an associated pcre[16|32]_extra structure, - or is NULL - tables Pointer to character tables, or NULL to - set the built-in default --The result is 0 for success, a negative PCRE_ERROR_xxx value otherwise. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_refcount.html b/libs/Pcre16/docs/doc/html/pcre_refcount.html deleted file mode 100644 index bfb92e6d8a..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_refcount.html +++ /dev/null @@ -1,51 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--int pcre_refcount(pcre *code, int adjust); -
--int pcre16_refcount(pcre16 *code, int adjust); -
--int pcre32_refcount(pcre32 *code, int adjust); -
--This function is used to maintain a reference count inside a data block that -contains a compiled pattern. Its arguments are: -
- code Compiled regular expression - adjust Adjustment to reference value --The yield of the function is the adjusted reference value, which is constrained -to lie between 0 and 65535. - -
-There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_study.html b/libs/Pcre16/docs/doc/html/pcre_study.html deleted file mode 100644 index af82f11409..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_study.html +++ /dev/null @@ -1,68 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
-
-pcre_extra *pcre_study(const pcre *code, int options,
- const char **errptr);
-
-
-pcre16_extra *pcre16_study(const pcre16 *code, int options,
- const char **errptr);
-
-
-pcre32_extra *pcre32_study(const pcre32 *code, int options,
- const char **errptr);
-
-This function studies a compiled pattern, to see if additional information can -be extracted that might speed up matching. Its arguments are: -
- code A compiled regular expression - options Options for pcre[16|32]_study() - errptr Where to put an error message --If the function succeeds, it returns a value that can be passed to -pcre[16|32]_exec() or pcre[16|32]_dfa_exec() via their extra -arguments. - -
-If the function returns NULL, either it could not find any additional -information, or there was an error. You can tell the difference by looking at -the error value. It is NULL in first case. -
--The only option is PCRE_STUDY_JIT_COMPILE. It requests just-in-time compilation -if possible. If PCRE has been compiled without JIT support, this option is -ignored. See the -pcrejit -page for further details. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_utf16_to_host_byte_order.html b/libs/Pcre16/docs/doc/html/pcre_utf16_to_host_byte_order.html deleted file mode 100644 index 18e7788f68..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_utf16_to_host_byte_order.html +++ /dev/null @@ -1,57 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--int pcre16_utf16_to_host_byte_order(PCRE_UCHAR16 *output, - PCRE_SPTR16 input, int length, int *host_byte_order, - int keep_boms); -
--This function, which exists only in the 16-bit library, converts a UTF-16 -string to the correct order for the current host, taking account of any byte -order marks (BOMs) within the string. Its arguments are: -
- output pointer to output buffer, may be the same as input - input pointer to input buffer - length number of 16-bit units in the input, or negative for - a zero-terminated string - host_byte_order a NULL value or a non-zero value pointed to means - start in host byte order - keep_boms if non-zero, BOMs are copied to the output string --The result of the function is the number of 16-bit units placed into the output -buffer, including the zero terminator if the string was zero-terminated. - -
-If host_byte_order is not NULL, it is set to indicate the byte order that -is current at the end of the string. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_utf32_to_host_byte_order.html b/libs/Pcre16/docs/doc/html/pcre_utf32_to_host_byte_order.html deleted file mode 100644 index 772ae40cd9..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_utf32_to_host_byte_order.html +++ /dev/null @@ -1,57 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--int pcre32_utf32_to_host_byte_order(PCRE_UCHAR32 *output, - PCRE_SPTR32 input, int length, int *host_byte_order, - int keep_boms); -
--This function, which exists only in the 32-bit library, converts a UTF-32 -string to the correct order for the current host, taking account of any byte -order marks (BOMs) within the string. Its arguments are: -
- output pointer to output buffer, may be the same as input - input pointer to input buffer - length number of 32-bit units in the input, or negative for - a zero-terminated string - host_byte_order a NULL value or a non-zero value pointed to means - start in host byte order - keep_boms if non-zero, BOMs are copied to the output string --The result of the function is the number of 32-bit units placed into the output -buffer, including the zero terminator if the string was zero-terminated. - -
-If host_byte_order is not NULL, it is set to indicate the byte order that -is current at the end of the string. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcre_version.html b/libs/Pcre16/docs/doc/html/pcre_version.html deleted file mode 100644 index d33e718955..0000000000 --- a/libs/Pcre16/docs/doc/html/pcre_version.html +++ /dev/null @@ -1,46 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SYNOPSIS
-
-
-#include <pcre.h> -
--const char *pcre_version(void); -
--const char *pcre16_version(void); -
--const char *pcre32_version(void); -
--This function (even in the 16-bit and 32-bit libraries) returns a -zero-terminated, 8-bit character string that gives the version number of the -PCRE library and the date of its release. -
--There is a complete description of the PCRE native API in the -pcreapi -page and a description of the POSIX API in the -pcreposix -page. -
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcreapi.html b/libs/Pcre16/docs/doc/html/pcreapi.html deleted file mode 100644 index 2d7adf185a..0000000000 --- a/libs/Pcre16/docs/doc/html/pcreapi.html +++ /dev/null @@ -1,2921 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcre.h> -
-
-pcre *pcre_compile(const char *pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre *pcre_compile2(const char *pattern, int options,
- int *errorcodeptr,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre_extra *pcre_study(const pcre *code, int options,
- const char **errptr);
-
-
-void pcre_free_study(pcre_extra *extra);
-
-
-int pcre_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize);
-
-
-int pcre_dfa_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- int *workspace, int wscount);
-
-int pcre_copy_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- char *buffer, int buffersize);
-
-
-int pcre_copy_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber, char *buffer,
- int buffersize);
-
-
-int pcre_get_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- const char **stringptr);
-
-
-int pcre_get_stringnumber(const pcre *code,
- const char *name);
-
-
-int pcre_get_stringtable_entries(const pcre *code,
- const char *name, char **first, char **last);
-
-
-int pcre_get_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber,
- const char **stringptr);
-
-
-int pcre_get_substring_list(const char *subject,
- int *ovector, int stringcount, const char ***listptr);
-
-
-void pcre_free_substring(const char *stringptr);
-
-
-void pcre_free_substring_list(const char **stringptr);
-
-int pcre_jit_exec(const pcre *code, const pcre_extra *extra,
- const char *subject, int length, int startoffset,
- int options, int *ovector, int ovecsize,
- pcre_jit_stack *jstack);
-
-
-pcre_jit_stack *pcre_jit_stack_alloc(int startsize, int maxsize);
-
-
-void pcre_jit_stack_free(pcre_jit_stack *stack);
-
-
-void pcre_assign_jit_stack(pcre_extra *extra,
- pcre_jit_callback callback, void *data);
-
-
-const unsigned char *pcre_maketables(void);
-
-
-int pcre_fullinfo(const pcre *code, const pcre_extra *extra,
- int what, void *where);
-
-
-int pcre_refcount(pcre *code, int adjust);
-
-
-int pcre_config(int what, void *where);
-
-
-const char *pcre_version(void);
-
-
-int pcre_pattern_to_host_byte_order(pcre *code,
- pcre_extra *extra, const unsigned char *tables);
-
-void *(*pcre_malloc)(size_t);
-
-
-void (*pcre_free)(void *);
-
-
-void *(*pcre_stack_malloc)(size_t);
-
-
-void (*pcre_stack_free)(void *);
-
-
-int (*pcre_callout)(pcre_callout_block *);
-
-
-int (*pcre_stack_guard)(void);
-
-As well as support for 8-bit character strings, PCRE also supports 16-bit -strings (from release 8.30) and 32-bit strings (from release 8.32), by means of -two additional libraries. They can be built as well as, or instead of, the -8-bit library. To avoid too much complication, this document describes the -8-bit versions of the functions, with only occasional references to the 16-bit -and 32-bit libraries. -
--The 16-bit and 32-bit functions operate in the same way as their 8-bit -counterparts; they just use different data types for their arguments and -results, and their names start with pcre16_ or pcre32_ instead of -pcre_. For every option that has UTF8 in its name (for example, -PCRE_UTF8), there are corresponding 16-bit and 32-bit names with UTF8 replaced -by UTF16 or UTF32, respectively. This facility is in fact just cosmetic; the -16-bit and 32-bit option names define the same bit values. -
--References to bytes and UTF-8 in this document should be read as references to -16-bit data units and UTF-16 when using the 16-bit library, or 32-bit data -units and UTF-32 when using the 32-bit library, unless specified otherwise. -More details of the specific differences for the 16-bit and 32-bit libraries -are given in the -pcre16 -and -pcre32 -pages. -
--PCRE has its own native API, which is described in this document. There are -also some wrapper functions (for the 8-bit library only) that correspond to the -POSIX regular expression API, but they do not give access to all the -functionality. They are described in the -pcreposix -documentation. Both of these APIs define a set of C function calls. A C++ -wrapper (again for the 8-bit library only) is also distributed with PCRE. It is -documented in the -pcrecpp -page. -
--The native API C function prototypes are defined in the header file -pcre.h, and on Unix-like systems the (8-bit) library itself is called -libpcre. It can normally be accessed by adding -lpcre to the -command for linking an application that uses PCRE. The header file defines the -macros PCRE_MAJOR and PCRE_MINOR to contain the major and minor release numbers -for the library. Applications can use these to include support for different -releases of PCRE. -
--In a Windows environment, if you want to statically link an application program -against a non-dll pcre.a file, you must define PCRE_STATIC before -including pcre.h or pcrecpp.h, because otherwise the -pcre_malloc() and pcre_free() exported functions will be declared -__declspec(dllimport), with unwanted results. -
--The functions pcre_compile(), pcre_compile2(), pcre_study(), -and pcre_exec() are used for compiling and matching regular expressions -in a Perl-compatible manner. A sample program that demonstrates the simplest -way of using them is provided in the file called pcredemo.c in the PCRE -source distribution. A listing of this program is given in the -pcredemo -documentation, and the -pcresample -documentation describes how to compile and run it. -
--Just-in-time compiler support is an optional feature of PCRE that can be built -in appropriate hardware environments. It greatly speeds up the matching -performance of many patterns. Simple programs can easily request that it be -used if available, by setting an option that is ignored when it is not -relevant. More complicated programs might need to make use of the functions -pcre_jit_stack_alloc(), pcre_jit_stack_free(), and -pcre_assign_jit_stack() in order to control the JIT code's memory usage. -
--From release 8.32 there is also a direct interface for JIT execution, which -gives improved performance. The JIT-specific functions are discussed in the -pcrejit -documentation. -
--A second matching function, pcre_dfa_exec(), which is not -Perl-compatible, is also provided. This uses a different algorithm for the -matching. The alternative algorithm finds all possible matches (at a given -point in the subject), and scans the subject just once (unless there are -lookbehind assertions). However, this algorithm does not return captured -substrings. A description of the two matching algorithms and their advantages -and disadvantages is given in the -pcrematching -documentation. -
--In addition to the main compiling and matching functions, there are convenience -functions for extracting captured substrings from a subject string that is -matched by pcre_exec(). They are: -
- pcre_copy_substring() - pcre_copy_named_substring() - pcre_get_substring() - pcre_get_named_substring() - pcre_get_substring_list() - pcre_get_stringnumber() - pcre_get_stringtable_entries() --pcre_free_substring() and pcre_free_substring_list() are also -provided, to free the memory used for extracted strings. - -
-The function pcre_maketables() is used to build a set of character tables -in the current locale for passing to pcre_compile(), pcre_exec(), -or pcre_dfa_exec(). This is an optional facility that is provided for -specialist use. Most commonly, no special tables are passed, in which case -internal tables that are generated when PCRE is built are used. -
--The function pcre_fullinfo() is used to find out information about a -compiled pattern. The function pcre_version() returns a pointer to a -string containing the version of PCRE and its date of release. -
--The function pcre_refcount() maintains a reference count in a data block -containing a compiled pattern. This is provided for the benefit of -object-oriented applications. -
--The global variables pcre_malloc and pcre_free initially contain -the entry points of the standard malloc() and free() functions, -respectively. PCRE calls the memory management functions via these variables, -so a calling program can replace them if it wishes to intercept the calls. This -should be done before calling any PCRE functions. -
--The global variables pcre_stack_malloc and pcre_stack_free are also -indirections to memory management functions. These special functions are used -only when PCRE is compiled to use the heap for remembering data, instead of -recursive function calls, when running the pcre_exec() function. See the -pcrebuild -documentation for details of how to do this. It is a non-standard way of -building PCRE, for use in environments that have limited stacks. Because of the -greater use of memory management, it runs more slowly. Separate functions are -provided so that special-purpose external code can be used for this case. When -used, these functions always allocate memory blocks of the same size. There is -a discussion about PCRE's stack usage in the -pcrestack -documentation. -
--The global variable pcre_callout initially contains NULL. It can be set -by the caller to a "callout" function, which PCRE will then call at specified -points during a matching operation. Details are given in the -pcrecallout -documentation. -
--The global variable pcre_stack_guard initially contains NULL. It can be -set by the caller to a function that is called by PCRE whenever it starts -to compile a parenthesized part of a pattern. When parentheses are nested, PCRE -uses recursive function calls, which use up the system stack. This function is -provided so that applications with restricted stacks can force a compilation -error if the stack runs out. The function should return zero if all is well, or -non-zero to force an error. -
--PCRE supports five different conventions for indicating line breaks in -strings: a single CR (carriage return) character, a single LF (linefeed) -character, the two-character sequence CRLF, any of the three preceding, or any -Unicode newline sequence. The Unicode newline sequences are the three just -mentioned, plus the single characters VT (vertical tab, U+000B), FF (form feed, -U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS -(paragraph separator, U+2029). -
--Each of the first three conventions is used by at least one operating system as -its standard newline sequence. When PCRE is built, a default can be specified. -The default default is LF, which is the Unix standard. When PCRE is run, the -default can be overridden, either when a pattern is compiled, or when it is -matched. -
--At compile time, the newline convention can be specified by the options -argument of pcre_compile(), or it can be specified by special text at the -start of the pattern itself; this overrides any other settings. See the -pcrepattern -page for details of the special character sequences. -
--In the PCRE documentation the word "newline" is used to mean "the character or -pair of characters that indicate a line break". The choice of newline -convention affects the handling of the dot, circumflex, and dollar -metacharacters, the handling of #-comments in /x mode, and, when CRLF is a -recognized line ending sequence, the match position advancement for a -non-anchored pattern. There is more detail about this in the -section on pcre_exec() options -below. -
--The choice of newline convention does not affect the interpretation of -the \n or \r escape sequences, nor does it affect what \R matches, which is -controlled in a similar way, but by separate options. -
--The PCRE functions can be used in multi-threading applications, with the -proviso that the memory management functions pointed to by pcre_malloc, -pcre_free, pcre_stack_malloc, and pcre_stack_free, and the -callout and stack-checking functions pointed to by pcre_callout and -pcre_stack_guard, are shared by all threads. -
--The compiled form of a regular expression is not altered during matching, so -the same compiled pattern can safely be used by several threads at once. -
--If the just-in-time optimization feature is being used, it needs separate -memory stack areas for each thread. See the -pcrejit -documentation for more details. -
--The compiled form of a regular expression can be saved and re-used at a later -time, possibly by a different program, and even on a host other than the one on -which it was compiled. Details are given in the -pcreprecompile -documentation, which includes a description of the -pcre_pattern_to_host_byte_order() function. However, compiling a regular -expression with one version of PCRE for use with a different version is not -guaranteed to work and may cause crashes. -
--int pcre_config(int what, void *where); -
--The function pcre_config() makes it possible for a PCRE client to -discover which optional features have been compiled into the PCRE library. The -pcrebuild -documentation has more details about these optional features. -
--The first argument for pcre_config() is an integer, specifying which -information is required; the second argument is a pointer to a variable into -which the information is placed. The returned value is zero on success, or the -negative error code PCRE_ERROR_BADOPTION if the value in the first argument is -not recognized. The following information is available: -
- PCRE_CONFIG_UTF8 --The output is an integer that is set to one if UTF-8 support is available; -otherwise it is set to zero. This value should normally be given to the 8-bit -version of this function, pcre_config(). If it is given to the 16-bit -or 32-bit version of this function, the result is PCRE_ERROR_BADOPTION. -
- PCRE_CONFIG_UTF16 --The output is an integer that is set to one if UTF-16 support is available; -otherwise it is set to zero. This value should normally be given to the 16-bit -version of this function, pcre16_config(). If it is given to the 8-bit -or 32-bit version of this function, the result is PCRE_ERROR_BADOPTION. -
- PCRE_CONFIG_UTF32 --The output is an integer that is set to one if UTF-32 support is available; -otherwise it is set to zero. This value should normally be given to the 32-bit -version of this function, pcre32_config(). If it is given to the 8-bit -or 16-bit version of this function, the result is PCRE_ERROR_BADOPTION. -
- PCRE_CONFIG_UNICODE_PROPERTIES --The output is an integer that is set to one if support for Unicode character -properties is available; otherwise it is set to zero. -
- PCRE_CONFIG_JIT --The output is an integer that is set to one if support for just-in-time -compiling is available; otherwise it is set to zero. -
- PCRE_CONFIG_JITTARGET --The output is a pointer to a zero-terminated "const char *" string. If JIT -support is available, the string contains the name of the architecture for -which the JIT compiler is configured, for example "x86 32bit (little endian + -unaligned)". If JIT support is not available, the result is NULL. -
- PCRE_CONFIG_NEWLINE --The output is an integer whose value specifies the default character sequence -that is recognized as meaning "newline". The values that are supported in -ASCII/Unicode environments are: 10 for LF, 13 for CR, 3338 for CRLF, -2 for -ANYCRLF, and -1 for ANY. In EBCDIC environments, CR, ANYCRLF, and ANY yield the -same values. However, the value for LF is normally 21, though some EBCDIC -environments use 37. The corresponding values for CRLF are 3349 and 3365. The -default should normally correspond to the standard sequence for your operating -system. -
- PCRE_CONFIG_BSR --The output is an integer whose value indicates what character sequences the \R -escape sequence matches by default. A value of 0 means that \R matches any -Unicode line ending sequence; a value of 1 means that \R matches only CR, LF, -or CRLF. The default can be overridden when a pattern is compiled or matched. -
- PCRE_CONFIG_LINK_SIZE --The output is an integer that contains the number of bytes used for internal -linkage in compiled regular expressions. For the 8-bit library, the value can -be 2, 3, or 4. For the 16-bit library, the value is either 2 or 4 and is still -a number of bytes. For the 32-bit library, the value is either 2 or 4 and is -still a number of bytes. The default value of 2 is sufficient for all but the -most massive patterns, since it allows the compiled pattern to be up to 64K in -size. Larger values allow larger regular expressions to be compiled, at the -expense of slower matching. -
- PCRE_CONFIG_POSIX_MALLOC_THRESHOLD --The output is an integer that contains the threshold above which the POSIX -interface uses malloc() for output vectors. Further details are given in -the -pcreposix -documentation. -
- PCRE_CONFIG_PARENS_LIMIT --The output is a long integer that gives the maximum depth of nesting of -parentheses (of any kind) in a pattern. This limit is imposed to cap the amount -of system stack used when a pattern is compiled. It is specified when PCRE is -built; the default is 250. This limit does not take into account the stack that -may already be used by the calling application. For finer control over -compilation stack usage, you can set a pointer to an external checking function -in pcre_stack_guard. -
- PCRE_CONFIG_MATCH_LIMIT --The output is a long integer that gives the default limit for the number of -internal matching function calls in a pcre_exec() execution. Further -details are given with pcre_exec() below. -
- PCRE_CONFIG_MATCH_LIMIT_RECURSION --The output is a long integer that gives the default limit for the depth of -recursion when calling the internal matching function in a pcre_exec() -execution. Further details are given with pcre_exec() below. -
- PCRE_CONFIG_STACKRECURSE --The output is an integer that is set to one if internal recursion when running -pcre_exec() is implemented by recursive function calls that use the stack -to remember their state. This is the usual way that PCRE is compiled. The -output is zero if PCRE was compiled to use blocks of data on the heap instead -of recursive function calls. In this case, pcre_stack_malloc and -pcre_stack_free are called to manage memory blocks on the heap, thus -avoiding the use of the stack. - -
-pcre *pcre_compile(const char *pattern, int options,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-
-pcre *pcre_compile2(const char *pattern, int options,
- int *errorcodeptr,
- const char **errptr, int *erroffset,
- const unsigned char *tableptr);
-
-Either of the functions pcre_compile() or pcre_compile2() can be -called to compile a pattern into an internal form. The only difference between -the two interfaces is that pcre_compile2() has an additional argument, -errorcodeptr, via which a numerical error code can be returned. To avoid -too much repetition, we refer just to pcre_compile() below, but the -information applies equally to pcre_compile2(). -
--The pattern is a C string terminated by a binary zero, and is passed in the -pattern argument. A pointer to a single block of memory that is obtained -via pcre_malloc is returned. This contains the compiled code and related -data. The pcre type is defined for the returned block; this is a typedef -for a structure whose contents are not externally defined. It is up to the -caller to free the memory (via pcre_free) when it is no longer required. -
--Although the compiled code of a PCRE regex is relocatable, that is, it does not -depend on memory location, the complete pcre data block is not -fully relocatable, because it may contain a copy of the tableptr -argument, which is an address (see below). -
--The options argument contains various bit settings that affect the -compilation. It should be zero if no options are required. The available -options are described below. Some of them (in particular, those that are -compatible with Perl, but some others as well) can also be set and unset from -within the pattern (see the detailed description in the -pcrepattern -documentation). For those options that can be different in different parts of -the pattern, the contents of the options argument specifies their -settings at the start of compilation and execution. The PCRE_ANCHORED, -PCRE_BSR_xxx, PCRE_NEWLINE_xxx, PCRE_NO_UTF8_CHECK, and -PCRE_NO_START_OPTIMIZE options can be set at the time of matching as well as at -compile time. -
--If errptr is NULL, pcre_compile() returns NULL immediately. -Otherwise, if compilation of a pattern fails, pcre_compile() returns -NULL, and sets the variable pointed to by errptr to point to a textual -error message. This is a static string that is part of the library. You must -not try to free it. Normally, the offset from the start of the pattern to the -data unit that was being processed when the error was discovered is placed in -the variable pointed to by erroffset, which must not be NULL (if it is, -an immediate error is given). However, for an invalid UTF-8 or UTF-16 string, -the offset is that of the first data unit of the failing character. -
--Some errors are not detected until the whole pattern has been scanned; in these -cases, the offset passed back is the length of the pattern. Note that the -offset is in data units, not characters, even in a UTF mode. It may sometimes -point into the middle of a UTF-8 or UTF-16 character. -
--If pcre_compile2() is used instead of pcre_compile(), and the -errorcodeptr argument is not NULL, a non-zero error code number is -returned via this argument in the event of an error. This is in addition to the -textual error message. Error codes and messages are listed below. -
--If the final argument, tableptr, is NULL, PCRE uses a default set of -character tables that are built when PCRE is compiled, using the default C -locale. Otherwise, tableptr must be an address that is the result of a -call to pcre_maketables(). This value is stored with the compiled -pattern, and used again by pcre_exec() and pcre_dfa_exec() when the -pattern is matched. For more discussion, see the section on locale support -below. -
--This code fragment shows a typical straightforward call to pcre_compile(): -
- pcre *re; - const char *error; - int erroffset; - re = pcre_compile( - "^A.*Z", /* the pattern */ - 0, /* default options */ - &error, /* for error message */ - &erroffset, /* for error offset */ - NULL); /* use default character tables */ --The following names for option bits are defined in the pcre.h header -file: -
- PCRE_ANCHORED --If this bit is set, the pattern is forced to be "anchored", that is, it is -constrained to match only at the first matching point in the string that is -being searched (the "subject string"). This effect can also be achieved by -appropriate constructs in the pattern itself, which is the only way to do it in -Perl. -
- PCRE_AUTO_CALLOUT --If this bit is set, pcre_compile() automatically inserts callout items, -all with number 255, before each pattern item. For discussion of the callout -facility, see the -pcrecallout -documentation. -
- PCRE_BSR_ANYCRLF - PCRE_BSR_UNICODE --These options (which are mutually exclusive) control what the \R escape -sequence matches. The choice is either to match only CR, LF, or CRLF, or to -match any Unicode newline sequence. The default is specified when PCRE is -built. It can be overridden from within the pattern, or by setting an option -when a compiled pattern is matched. -
- PCRE_CASELESS --If this bit is set, letters in the pattern match both upper and lower case -letters. It is equivalent to Perl's /i option, and it can be changed within a -pattern by a (?i) option setting. In UTF-8 mode, PCRE always understands the -concept of case for characters whose values are less than 128, so caseless -matching is always possible. For characters with higher values, the concept of -case is supported if PCRE is compiled with Unicode property support, but not -otherwise. If you want to use caseless matching for characters 128 and above, -you must ensure that PCRE is compiled with Unicode property support as well as -with UTF-8 support. -
- PCRE_DOLLAR_ENDONLY --If this bit is set, a dollar metacharacter in the pattern matches only at the -end of the subject string. Without this option, a dollar also matches -immediately before a newline at the end of the string (but not before any other -newlines). The PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set. -There is no equivalent to this option in Perl, and no way to set it within a -pattern. -
- PCRE_DOTALL --If this bit is set, a dot metacharacter in the pattern matches a character of -any value, including one that indicates a newline. However, it only ever -matches one character, even if newlines are coded as CRLF. Without this option, -a dot does not match when the current position is at a newline. This option is -equivalent to Perl's /s option, and it can be changed within a pattern by a -(?s) option setting. A negative class such as [^a] always matches newline -characters, independent of the setting of this option. -
- PCRE_DUPNAMES --If this bit is set, names used to identify capturing subpatterns need not be -unique. This can be helpful for certain types of pattern when it is known that -only one instance of the named subpattern can ever be matched. There are more -details of named subpatterns below; see also the -pcrepattern -documentation. -
- PCRE_EXTENDED --If this bit is set, most white space characters in the pattern are totally -ignored except when escaped or inside a character class. However, white space -is not allowed within sequences such as (?> that introduce various -parenthesized subpatterns, nor within a numerical quantifier such as {1,3}. -However, ignorable white space is permitted between an item and a following -quantifier and between a quantifier and a following + that indicates -possessiveness. - -
-White space did not used to include the VT character (code 11), because Perl -did not treat this character as white space. However, Perl changed at release -5.18, so PCRE followed at release 8.34, and VT is now treated as white space. -
--PCRE_EXTENDED also causes characters between an unescaped # outside a character -class and the next newline, inclusive, to be ignored. PCRE_EXTENDED is -equivalent to Perl's /x option, and it can be changed within a pattern by a -(?x) option setting. -
--Which characters are interpreted as newlines is controlled by the options -passed to pcre_compile() or by a special sequence at the start of the -pattern, as described in the section entitled -"Newline conventions" -in the pcrepattern documentation. Note that the end of this type of -comment is a literal newline sequence in the pattern; escape sequences that -happen to represent a newline do not count. -
--This option makes it possible to include comments inside complicated patterns. -Note, however, that this applies only to data characters. White space characters -may never appear within special character sequences in a pattern, for example -within the sequence (?( that introduces a conditional subpattern. -
- PCRE_EXTRA --This option was invented in order to turn on additional functionality of PCRE -that is incompatible with Perl, but it is currently of very little use. When -set, any backslash in a pattern that is followed by a letter that has no -special meaning causes an error, thus reserving these combinations for future -expansion. By default, as in Perl, a backslash followed by a letter with no -special meaning is treated as a literal. (Perl can, however, be persuaded to -give an error for this, by running it with the -w option.) There are at present -no other features controlled by this option. It can also be set by a (?X) -option setting within a pattern. -
- PCRE_FIRSTLINE --If this option is set, an unanchored pattern is required to match before or at -the first newline in the subject string, though the matched text may continue -over the newline. -
- PCRE_JAVASCRIPT_COMPAT --If this option is set, PCRE's behaviour is changed in some ways so that it is -compatible with JavaScript rather than Perl. The changes are as follows: - -
-(1) A lone closing square bracket in a pattern causes a compile-time error, -because this is illegal in JavaScript (by default it is treated as a data -character). Thus, the pattern AB]CD becomes illegal when this option is set. -
--(2) At run time, a back reference to an unset subpattern group matches an empty -string (by default this causes the current matching alternative to fail). A -pattern such as (\1)(a) succeeds when this option is set (assuming it can find -an "a" in the subject), whereas it fails by default, for Perl compatibility. -
--(3) \U matches an upper case "U" character; by default \U causes a compile -time error (Perl uses \U to upper case subsequent characters). -
--(4) \u matches a lower case "u" character unless it is followed by four -hexadecimal digits, in which case the hexadecimal number defines the code point -to match. By default, \u causes a compile time error (Perl uses it to upper -case the following character). -
--(5) \x matches a lower case "x" character unless it is followed by two -hexadecimal digits, in which case the hexadecimal number defines the code point -to match. By default, as in Perl, a hexadecimal number is always expected after -\x, but it may have zero, one, or two digits (so, for example, \xz matches a -binary zero character followed by z). -
- PCRE_MULTILINE --By default, for the purposes of matching "start of line" and "end of line", -PCRE treats the subject string as consisting of a single line of characters, -even if it actually contains newlines. The "start of line" metacharacter (^) -matches only at the start of the string, and the "end of line" metacharacter -($) matches only at the end of the string, or before a terminating newline -(except when PCRE_DOLLAR_ENDONLY is set). Note, however, that unless -PCRE_DOTALL is set, the "any character" metacharacter (.) does not match at a -newline. This behaviour (for ^, $, and dot) is the same as Perl. - -
-When PCRE_MULTILINE it is set, the "start of line" and "end of line" constructs -match immediately following or immediately before internal newlines in the -subject string, respectively, as well as at the very start and end. This is -equivalent to Perl's /m option, and it can be changed within a pattern by a -(?m) option setting. If there are no newlines in a subject string, or no -occurrences of ^ or $ in a pattern, setting PCRE_MULTILINE has no effect. -
- PCRE_NEVER_UTF --This option locks out interpretation of the pattern as UTF-8 (or UTF-16 or -UTF-32 in the 16-bit and 32-bit libraries). In particular, it prevents the -creator of the pattern from switching to UTF interpretation by starting the -pattern with (*UTF). This may be useful in applications that process patterns -from external sources. The combination of PCRE_UTF8 and PCRE_NEVER_UTF also -causes an error. -
- PCRE_NEWLINE_CR - PCRE_NEWLINE_LF - PCRE_NEWLINE_CRLF - PCRE_NEWLINE_ANYCRLF - PCRE_NEWLINE_ANY --These options override the default newline definition that was chosen when PCRE -was built. Setting the first or the second specifies that a newline is -indicated by a single character (CR or LF, respectively). Setting -PCRE_NEWLINE_CRLF specifies that a newline is indicated by the two-character -CRLF sequence. Setting PCRE_NEWLINE_ANYCRLF specifies that any of the three -preceding sequences should be recognized. Setting PCRE_NEWLINE_ANY specifies -that any Unicode newline sequence should be recognized. - -
-In an ASCII/Unicode environment, the Unicode newline sequences are the three -just mentioned, plus the single characters VT (vertical tab, U+000B), FF (form -feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS -(paragraph separator, U+2029). For the 8-bit library, the last two are -recognized only in UTF-8 mode. -
--When PCRE is compiled to run in an EBCDIC (mainframe) environment, the code for -CR is 0x0d, the same as ASCII. However, the character code for LF is normally -0x15, though in some EBCDIC environments 0x25 is used. Whichever of these is -not LF is made to correspond to Unicode's NEL character. EBCDIC codes are all -less than 256. For more details, see the -pcrebuild -documentation. -
--The newline setting in the options word uses three bits that are treated -as a number, giving eight possibilities. Currently only six are used (default -plus the five values above). This means that if you set more than one newline -option, the combination may or may not be sensible. For example, -PCRE_NEWLINE_CR with PCRE_NEWLINE_LF is equivalent to PCRE_NEWLINE_CRLF, but -other combinations may yield unused numbers and cause an error. -
--The only time that a line break in a pattern is specially recognized when -compiling is when PCRE_EXTENDED is set. CR and LF are white space characters, -and so are ignored in this mode. Also, an unescaped # outside a character class -indicates a comment that lasts until after the next line break sequence. In -other circumstances, line break sequences in patterns are treated as literal -data. -
--The newline option that is set at compile time becomes the default that is used -for pcre_exec() and pcre_dfa_exec(), but it can be overridden. -
- PCRE_NO_AUTO_CAPTURE --If this option is set, it disables the use of numbered capturing parentheses in -the pattern. Any opening parenthesis that is not followed by ? behaves as if it -were followed by ?: but named parentheses can still be used for capturing (and -they acquire numbers in the usual way). There is no equivalent of this option -in Perl. -
- PCRE_NO_AUTO_POSSESS --If this option is set, it disables "auto-possessification". This is an -optimization that, for example, turns a+b into a++b in order to avoid -backtracks into a+ that can never be successful. However, if callouts are in -use, auto-possessification means that some of them are never taken. You can set -this option if you want the matching functions to do a full unoptimized search -and run all the callouts, but it is mainly provided for testing purposes. -
- PCRE_NO_START_OPTIMIZE --This is an option that acts at matching time; that is, it is really an option -for pcre_exec() or pcre_dfa_exec(). If it is set at compile time, -it is remembered with the compiled pattern and assumed at matching time. This -is necessary if you want to use JIT execution, because the JIT compiler needs -to know whether or not this option is set. For details see the discussion of -PCRE_NO_START_OPTIMIZE -below. -
- PCRE_UCP --This option changes the way PCRE processes \B, \b, \D, \d, \S, \s, \W, -\w, and some of the POSIX character classes. By default, only ASCII characters -are recognized, but if PCRE_UCP is set, Unicode properties are used instead to -classify characters. More details are given in the section on -generic character types -in the -pcrepattern -page. If you set PCRE_UCP, matching one of the items it affects takes much -longer. The option is available only if PCRE has been compiled with Unicode -property support. -
- PCRE_UNGREEDY --This option inverts the "greediness" of the quantifiers so that they are not -greedy by default, but become greedy if followed by "?". It is not compatible -with Perl. It can also be set by a (?U) option setting within the pattern. -
- PCRE_UTF8 --This option causes PCRE to regard both the pattern and the subject as strings -of UTF-8 characters instead of single-byte strings. However, it is available -only when PCRE is built to include UTF support. If not, the use of this option -provokes an error. Details of how this option changes the behaviour of PCRE are -given in the -pcreunicode -page. -
- PCRE_NO_UTF8_CHECK --When PCRE_UTF8 is set, the validity of the pattern as a UTF-8 string is -automatically checked. There is a discussion about the -validity of UTF-8 strings -in the -pcreunicode -page. If an invalid UTF-8 sequence is found, pcre_compile() returns an -error. If you already know that your pattern is valid, and you want to skip -this check for performance reasons, you can set the PCRE_NO_UTF8_CHECK option. -When it is set, the effect of passing an invalid UTF-8 string as a pattern is -undefined. It may cause your program to crash or loop. Note that this option -can also be passed to pcre_exec() and pcre_dfa_exec(), to suppress -the validity checking of subject strings only. If the same string is being -matched many times, the option can be safely set for the second and subsequent -matchings to improve performance. - -
-The following table lists the error codes than may be returned by -pcre_compile2(), along with the error messages that may be returned by -both compiling functions. Note that error messages are always 8-bit ASCII -strings, even in 16-bit or 32-bit mode. As PCRE has developed, some error codes -have fallen out of use. To avoid confusion, they have not been re-used. -
- 0 no error - 1 \ at end of pattern - 2 \c at end of pattern - 3 unrecognized character follows \ - 4 numbers out of order in {} quantifier - 5 number too big in {} quantifier - 6 missing terminating ] for character class - 7 invalid escape sequence in character class - 8 range out of order in character class - 9 nothing to repeat - 10 [this code is not in use] - 11 internal error: unexpected repeat - 12 unrecognized character after (? or (?- - 13 POSIX named classes are supported only within a class - 14 missing ) - 15 reference to non-existent subpattern - 16 erroffset passed as NULL - 17 unknown option bit(s) set - 18 missing ) after comment - 19 [this code is not in use] - 20 regular expression is too large - 21 failed to get memory - 22 unmatched parentheses - 23 internal error: code overflow - 24 unrecognized character after (?< - 25 lookbehind assertion is not fixed length - 26 malformed number or name after (?( - 27 conditional group contains more than two branches - 28 assertion expected after (?( - 29 (?R or (?[+-]digits must be followed by ) - 30 unknown POSIX class name - 31 POSIX collating elements are not supported - 32 this version of PCRE is compiled without UTF support - 33 [this code is not in use] - 34 character value in \x{} or \o{} is too large - 35 invalid condition (?(0) - 36 \C not allowed in lookbehind assertion - 37 PCRE does not support \L, \l, \N{name}, \U, or \u - 38 number after (?C is > 255 - 39 closing ) for (?C expected - 40 recursive call could loop indefinitely - 41 unrecognized character after (?P - 42 syntax error in subpattern name (missing terminator) - 43 two named subpatterns have the same name - 44 invalid UTF-8 string (specifically UTF-8) - 45 support for \P, \p, and \X has not been compiled - 46 malformed \P or \p sequence - 47 unknown property name after \P or \p - 48 subpattern name is too long (maximum 32 characters) - 49 too many named subpatterns (maximum 10000) - 50 [this code is not in use] - 51 octal value is greater than \377 in 8-bit non-UTF-8 mode - 52 internal error: overran compiling workspace - 53 internal error: previously-checked referenced subpattern - not found - 54 DEFINE group contains more than one branch - 55 repeating a DEFINE group is not allowed - 56 inconsistent NEWLINE options - 57 \g is not followed by a braced, angle-bracketed, or quoted - name/number or by a plain number - 58 a numbered reference must not be zero - 59 an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT) - 60 (*VERB) not recognized or malformed - 61 number is too big - 62 subpattern name expected - 63 digit expected after (?+ - 64 ] is an invalid data character in JavaScript compatibility mode - 65 different names for subpatterns of the same number are - not allowed - 66 (*MARK) must have an argument - 67 this version of PCRE is not compiled with Unicode property - support - 68 \c must be followed by an ASCII character - 69 \k is not followed by a braced, angle-bracketed, or quoted name - 70 internal error: unknown opcode in find_fixedlength() - 71 \N is not supported in a class - 72 too many forward references - 73 disallowed Unicode code point (>= 0xd800 && <= 0xdfff) - 74 invalid UTF-16 string (specifically UTF-16) - 75 name is too long in (*MARK), (*PRUNE), (*SKIP), or (*THEN) - 76 character value in \u.... sequence is too large - 77 invalid UTF-32 string (specifically UTF-32) - 78 setting UTF is disabled by the application - 79 non-hex character in \x{} (closing brace missing?) - 80 non-octal character in \o{} (closing brace missing?) - 81 missing opening brace after \o - 82 parentheses are too deeply nested - 83 invalid range in character class - 84 group name must start with a non-digit - 85 parentheses are too deeply nested (stack check) --The numbers 32 and 10000 in errors 48 and 49 are defaults; different values may -be used if the limits were changed when PCRE was built. - -
-pcre_extra *pcre_study(const pcre *code, int options, - const char **errptr); -
--If a compiled pattern is going to be used several times, it is worth spending -more time analyzing it in order to speed up the time taken for matching. The -function pcre_study() takes a pointer to a compiled pattern as its first -argument. If studying the pattern produces additional information that will -help speed up matching, pcre_study() returns a pointer to a -pcre_extra block, in which the study_data field points to the -results of the study. -
--The returned value from pcre_study() can be passed directly to -pcre_exec() or pcre_dfa_exec(). However, a pcre_extra block -also contains other fields that can be set by the caller before the block is -passed; these are described -below -in the section on matching a pattern. -
--If studying the pattern does not produce any useful information, -pcre_study() returns NULL by default. In that circumstance, if the -calling program wants to pass any of the other fields to pcre_exec() or -pcre_dfa_exec(), it must set up its own pcre_extra block. However, -if pcre_study() is called with the PCRE_STUDY_EXTRA_NEEDED option, it -returns a pcre_extra block even if studying did not find any additional -information. It may still return NULL, however, if an error occurs in -pcre_study(). -
--The second argument of pcre_study() contains option bits. There are three -further options in addition to PCRE_STUDY_EXTRA_NEEDED: -
- PCRE_STUDY_JIT_COMPILE - PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE - PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE --If any of these are set, and the just-in-time compiler is available, the -pattern is further compiled into machine code that executes much faster than -the pcre_exec() interpretive matching function. If the just-in-time -compiler is not available, these options are ignored. All undefined bits in the -options argument must be zero. - -
-JIT compilation is a heavyweight optimization. It can take some time for -patterns to be analyzed, and for one-off matches and simple patterns the -benefit of faster execution might be offset by a much slower study time. -Not all patterns can be optimized by the JIT compiler. For those that cannot be -handled, matching automatically falls back to the pcre_exec() -interpreter. For more details, see the -pcrejit -documentation. -
--The third argument for pcre_study() is a pointer for an error message. If -studying succeeds (even if no data is returned), the variable it points to is -set to NULL. Otherwise it is set to point to a textual error message. This is a -static string that is part of the library. You must not try to free it. You -should test the error pointer for NULL after calling pcre_study(), to be -sure that it has run successfully. -
--When you are finished with a pattern, you can free the memory used for the -study data by calling pcre_free_study(). This function was added to the -API for release 8.20. For earlier versions, the memory could be freed with -pcre_free(), just like the pattern itself. This will still work in cases -where JIT optimization is not used, but it is advisable to change to the new -function when convenient. -
--This is a typical way in which pcre_study() is used (except that in a -real application there should be tests for errors): -
- int rc; - pcre *re; - pcre_extra *sd; - re = pcre_compile("pattern", 0, &error, &erroroffset, NULL); - sd = pcre_study( - re, /* result of pcre_compile() */ - 0, /* no options */ - &error); /* set to NULL or points to a message */ - rc = pcre_exec( /* see below for details of pcre_exec() options */ - re, sd, "subject", 7, 0, 0, ovector, 30); - ... - pcre_free_study(sd); - pcre_free(re); --Studying a pattern does two things: first, a lower bound for the length of -subject string that is needed to match the pattern is computed. This does not -mean that there are any strings of that length that match, but it does -guarantee that no shorter strings match. The value is used to avoid wasting -time by trying to match strings that are shorter than the lower bound. You can -find out the value in a calling program via the pcre_fullinfo() function. - -
-Studying a pattern is also useful for non-anchored patterns that do not have a -single fixed starting character. A bitmap of possible starting bytes is -created. This speeds up finding a position in the subject at which to start -matching. (In 16-bit mode, the bitmap is used for 16-bit values less than 256. -In 32-bit mode, the bitmap is used for 32-bit values less than 256.) -
--These two optimizations apply to both pcre_exec() and -pcre_dfa_exec(), and the information is also used by the JIT compiler. -The optimizations can be disabled by setting the PCRE_NO_START_OPTIMIZE option. -You might want to do this if your pattern contains callouts or (*MARK) and you -want to make use of these facilities in cases where matching fails. -
--PCRE_NO_START_OPTIMIZE can be specified at either compile time or execution -time. However, if PCRE_NO_START_OPTIMIZE is passed to pcre_exec(), (that -is, after any JIT compilation has happened) JIT execution is disabled. For JIT -execution to work with PCRE_NO_START_OPTIMIZE, the option must be set at -compile time. -
--There is a longer discussion of PCRE_NO_START_OPTIMIZE -below. -
--PCRE handles caseless matching, and determines whether characters are letters, -digits, or whatever, by reference to a set of tables, indexed by character -code point. When running in UTF-8 mode, or in the 16- or 32-bit libraries, this -applies only to characters with code points less than 256. By default, -higher-valued code points never match escapes such as \w or \d. However, if -PCRE is built with Unicode property support, all characters can be tested with -\p and \P, or, alternatively, the PCRE_UCP option can be set when a pattern -is compiled; this causes \w and friends to use Unicode property support -instead of the built-in tables. -
--The use of locales with Unicode is discouraged. If you are handling characters -with code points greater than 128, you should either use Unicode support, or -use locales, but not try to mix the two. -
--PCRE contains an internal set of tables that are used when the final argument -of pcre_compile() is NULL. These are sufficient for many applications. -Normally, the internal tables recognize only ASCII characters. However, when -PCRE is built, it is possible to cause the internal tables to be rebuilt in the -default "C" locale of the local system, which may cause them to be different. -
--The internal tables can always be overridden by tables supplied by the -application that calls PCRE. These may be created in a different locale from -the default. As more and more applications change to using Unicode, the need -for this locale support is expected to die away. -
--External tables are built by calling the pcre_maketables() function, -which has no arguments, in the relevant locale. The result can then be passed -to pcre_compile() as often as necessary. For example, to build and use -tables that are appropriate for the French locale (where accented characters -with values greater than 128 are treated as letters), the following code could -be used: -
- setlocale(LC_CTYPE, "fr_FR"); - tables = pcre_maketables(); - re = pcre_compile(..., tables); --The locale name "fr_FR" is used on Linux and other Unix-like systems; if you -are using Windows, the name for the French locale is "french". - -
-When pcre_maketables() runs, the tables are built in memory that is -obtained via pcre_malloc. It is the caller's responsibility to ensure -that the memory containing the tables remains available for as long as it is -needed. -
--The pointer that is passed to pcre_compile() is saved with the compiled -pattern, and the same tables are used via this pointer by pcre_study() -and also by pcre_exec() and pcre_dfa_exec(). Thus, for any single -pattern, compilation, studying and matching all happen in the same locale, but -different patterns can be processed in different locales. -
--It is possible to pass a table pointer or NULL (indicating the use of the -internal tables) to pcre_exec() or pcre_dfa_exec() (see the -discussion below in the section on matching a pattern). This facility is -provided for use with pre-compiled patterns that have been saved and reloaded. -Character tables are not saved with patterns, so if a non-standard table was -used at compile time, it must be provided again when the reloaded pattern is -matched. Attempting to use this facility to match a pattern in a different -locale from the one in which it was compiled is likely to lead to anomalous -(usually incorrect) results. -
--int pcre_fullinfo(const pcre *code, const pcre_extra *extra, - int what, void *where); -
--The pcre_fullinfo() function returns information about a compiled -pattern. It replaces the pcre_info() function, which was removed from the -library at version 8.30, after more than 10 years of obsolescence. -
--The first argument for pcre_fullinfo() is a pointer to the compiled -pattern. The second argument is the result of pcre_study(), or NULL if -the pattern was not studied. The third argument specifies which piece of -information is required, and the fourth argument is a pointer to a variable -to receive the data. The yield of the function is zero for success, or one of -the following negative numbers: -
- PCRE_ERROR_NULL the argument code was NULL - the argument where was NULL - PCRE_ERROR_BADMAGIC the "magic number" was not found - PCRE_ERROR_BADENDIANNESS the pattern was compiled with different - endianness - PCRE_ERROR_BADOPTION the value of what was invalid - PCRE_ERROR_UNSET the requested field is not set --The "magic number" is placed at the start of each compiled pattern as an simple -check against passing an arbitrary memory pointer. The endianness error can -occur if a compiled pattern is saved and reloaded on a different host. Here is -a typical call of pcre_fullinfo(), to obtain the length of the compiled -pattern: -
- int rc; - size_t length; - rc = pcre_fullinfo( - re, /* result of pcre_compile() */ - sd, /* result of pcre_study(), or NULL */ - PCRE_INFO_SIZE, /* what is required */ - &length); /* where to put the data */ --The possible values for the third argument are defined in pcre.h, and are -as follows: -
- PCRE_INFO_BACKREFMAX --Return the number of the highest back reference in the pattern. The fourth -argument should point to an int variable. Zero is returned if there are -no back references. -
- PCRE_INFO_CAPTURECOUNT --Return the number of capturing subpatterns in the pattern. The fourth argument -should point to an int variable. -
- PCRE_INFO_DEFAULT_TABLES --Return a pointer to the internal default character tables within PCRE. The -fourth argument should point to an unsigned char * variable. This -information call is provided for internal use by the pcre_study() -function. External callers can cause PCRE to use its internal tables by passing -a NULL table pointer. -
- PCRE_INFO_FIRSTBYTE (deprecated) --Return information about the first data unit of any matched string, for a -non-anchored pattern. The name of this option refers to the 8-bit library, -where data units are bytes. The fourth argument should point to an int -variable. Negative values are used for special cases. However, this means that -when the 32-bit library is in non-UTF-32 mode, the full 32-bit range of -characters cannot be returned. For this reason, this value is deprecated; use -PCRE_INFO_FIRSTCHARACTERFLAGS and PCRE_INFO_FIRSTCHARACTER instead. - -
-If there is a fixed first value, for example, the letter "c" from a pattern -such as (cat|cow|coyote), its value is returned. In the 8-bit library, the -value is always less than 256. In the 16-bit library the value can be up to -0xffff. In the 32-bit library the value can be up to 0x10ffff. -
-
-If there is no fixed first value, and if either
-
-
-(a) the pattern was compiled with the PCRE_MULTILINE option, and every branch
-starts with "^", or
-
-
-(b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set
-(if it were set, the pattern would be anchored),
-
-
--1 is returned, indicating that the pattern matches only at the start of a
-subject string or after any newline within the string. Otherwise -2 is
-returned. For anchored patterns, -2 is returned.
-
- PCRE_INFO_FIRSTCHARACTER --Return the value of the first data unit (non-UTF character) of any matched -string in the situation where PCRE_INFO_FIRSTCHARACTERFLAGS returns 1; -otherwise return 0. The fourth argument should point to an uint_t -variable. - -
-In the 8-bit library, the value is always less than 256. In the 16-bit library -the value can be up to 0xffff. In the 32-bit library in UTF-32 mode the value -can be up to 0x10ffff, and up to 0xffffffff when not using UTF-32 mode. -
- PCRE_INFO_FIRSTCHARACTERFLAGS --Return information about the first data unit of any matched string, for a -non-anchored pattern. The fourth argument should point to an int -variable. - -
-If there is a fixed first value, for example, the letter "c" from a pattern
-such as (cat|cow|coyote), 1 is returned, and the character value can be
-retrieved using PCRE_INFO_FIRSTCHARACTER. If there is no fixed first value, and
-if either
-
-
-(a) the pattern was compiled with the PCRE_MULTILINE option, and every branch
-starts with "^", or
-
-
-(b) every branch of the pattern starts with ".*" and PCRE_DOTALL is not set
-(if it were set, the pattern would be anchored),
-
-
-2 is returned, indicating that the pattern matches only at the start of a
-subject string or after any newline within the string. Otherwise 0 is
-returned. For anchored patterns, 0 is returned.
-
- PCRE_INFO_FIRSTTABLE --If the pattern was studied, and this resulted in the construction of a 256-bit -table indicating a fixed set of values for the first data unit in any matching -string, a pointer to the table is returned. Otherwise NULL is returned. The -fourth argument should point to an unsigned char * variable. -
- PCRE_INFO_HASCRORLF --Return 1 if the pattern contains any explicit matches for CR or LF characters, -otherwise 0. The fourth argument should point to an int variable. An -explicit match is either a literal CR or LF character, or \r or \n. -
- PCRE_INFO_JCHANGED --Return 1 if the (?J) or (?-J) option setting is used in the pattern, otherwise -0. The fourth argument should point to an int variable. (?J) and -(?-J) set and unset the local PCRE_DUPNAMES option, respectively. -
- PCRE_INFO_JIT --Return 1 if the pattern was studied with one of the JIT options, and -just-in-time compiling was successful. The fourth argument should point to an -int variable. A return value of 0 means that JIT support is not available -in this version of PCRE, or that the pattern was not studied with a JIT option, -or that the JIT compiler could not handle this particular pattern. See the -pcrejit -documentation for details of what can and cannot be handled. -
- PCRE_INFO_JITSIZE --If the pattern was successfully studied with a JIT option, return the size of -the JIT compiled code, otherwise return zero. The fourth argument should point -to a size_t variable. -
- PCRE_INFO_LASTLITERAL --Return the value of the rightmost literal data unit that must exist in any -matched string, other than at its start, if such a value has been recorded. The -fourth argument should point to an int variable. If there is no such -value, -1 is returned. For anchored patterns, a last literal value is recorded -only if it follows something of variable length. For example, for the pattern -/^a\d+z\d+/ the returned value is "z", but for /^a\dz\d/ the returned value -is -1. - -
-Since for the 32-bit library using the non-UTF-32 mode, this function is unable -to return the full 32-bit range of characters, this value is deprecated; -instead the PCRE_INFO_REQUIREDCHARFLAGS and PCRE_INFO_REQUIREDCHAR values should -be used. -
- PCRE_INFO_MATCH_EMPTY --Return 1 if the pattern can match an empty string, otherwise 0. The fourth -argument should point to an int variable. -
- PCRE_INFO_MATCHLIMIT --If the pattern set a match limit by including an item of the form -(*LIMIT_MATCH=nnnn) at the start, the value is returned. The fourth argument -should point to an unsigned 32-bit integer. If no such value has been set, the -call to pcre_fullinfo() returns the error PCRE_ERROR_UNSET. -
- PCRE_INFO_MAXLOOKBEHIND --Return the number of characters (NB not data units) in the longest lookbehind -assertion in the pattern. This information is useful when doing multi-segment -matching using the partial matching facilities. Note that the simple assertions -\b and \B require a one-character lookbehind. \A also registers a -one-character lookbehind, though it does not actually inspect the previous -character. This is to ensure that at least one character from the old segment -is retained when a new segment is processed. Otherwise, if there are no -lookbehinds in the pattern, \A might match incorrectly at the start of a new -segment. -
- PCRE_INFO_MINLENGTH --If the pattern was studied and a minimum length for matching subject strings -was computed, its value is returned. Otherwise the returned value is -1. The -value is a number of characters, which in UTF mode may be different from the -number of data units. The fourth argument should point to an int -variable. A non-negative value is a lower bound to the length of any matching -string. There may not be any strings of that length that do actually match, but -every string that does match is at least that long. -
- PCRE_INFO_NAMECOUNT - PCRE_INFO_NAMEENTRYSIZE - PCRE_INFO_NAMETABLE --PCRE supports the use of named as well as numbered capturing parentheses. The -names are just an additional way of identifying the parentheses, which still -acquire numbers. Several convenience functions such as -pcre_get_named_substring() are provided for extracting captured -substrings by name. It is also possible to extract the data directly, by first -converting the name to a number in order to access the correct pointers in the -output vector (described with pcre_exec() below). To do the conversion, -you need to use the name-to-number map, which is described by these three -values. - -
-The map consists of a number of fixed-size entries. PCRE_INFO_NAMECOUNT gives -the number of entries, and PCRE_INFO_NAMEENTRYSIZE gives the size of each -entry; both of these return an int value. The entry size depends on the -length of the longest name. PCRE_INFO_NAMETABLE returns a pointer to the first -entry of the table. This is a pointer to char in the 8-bit library, where -the first two bytes of each entry are the number of the capturing parenthesis, -most significant byte first. In the 16-bit library, the pointer points to -16-bit data units, the first of which contains the parenthesis number. In the -32-bit library, the pointer points to 32-bit data units, the first of which -contains the parenthesis number. The rest of the entry is the corresponding -name, zero terminated. -
--The names are in alphabetical order. If (?| is used to create multiple groups -with the same number, as described in the -section on duplicate subpattern numbers -in the -pcrepattern -page, the groups may be given the same name, but there is only one entry in the -table. Different names for groups of the same number are not permitted. -Duplicate names for subpatterns with different numbers are permitted, -but only if PCRE_DUPNAMES is set. They appear in the table in the order in -which they were found in the pattern. In the absence of (?| this is the order -of increasing number; when (?| is used this is not necessarily the case because -later subpatterns may have lower numbers. -
--As a simple example of the name/number table, consider the following pattern -after compilation by the 8-bit library (assume PCRE_EXTENDED is set, so white -space - including newlines - is ignored): -
- (?<date> (?<year>(\d\d)?\d\d) - (?<month>\d\d) - (?<day>\d\d) ) --There are four named subpatterns, so the table has four entries, and each entry -in the table is eight bytes long. The table is as follows, with non-printing -bytes shows in hexadecimal, and undefined bytes shown as ??: -
- 00 01 d a t e 00 ?? - 00 05 d a y 00 ?? ?? - 00 04 m o n t h 00 - 00 02 y e a r 00 ?? --When writing code to extract data from named subpatterns using the -name-to-number map, remember that the length of the entries is likely to be -different for each compiled pattern. -
- PCRE_INFO_OKPARTIAL --Return 1 if the pattern can be used for partial matching with -pcre_exec(), otherwise 0. The fourth argument should point to an -int variable. From release 8.00, this always returns 1, because the -restrictions that previously applied to partial matching have been lifted. The -pcrepartial -documentation gives details of partial matching. -
- PCRE_INFO_OPTIONS --Return a copy of the options with which the pattern was compiled. The fourth -argument should point to an unsigned long int variable. These option bits -are those specified in the call to pcre_compile(), modified by any -top-level option settings at the start of the pattern itself. In other words, -they are the options that will be in force when matching starts. For example, -if the pattern /(?im)abc(?-i)d/ is compiled with the PCRE_EXTENDED option, the -result is PCRE_CASELESS, PCRE_MULTILINE, and PCRE_EXTENDED. - -
-A pattern is automatically anchored by PCRE if all of its top-level -alternatives begin with one of the following: -
- ^ unless PCRE_MULTILINE is set - \A always - \G always - .* if PCRE_DOTALL is set and there are no back references to the subpattern in which .* appears --For such patterns, the PCRE_ANCHORED bit is set in the options returned by -pcre_fullinfo(). -
- PCRE_INFO_RECURSIONLIMIT --If the pattern set a recursion limit by including an item of the form -(*LIMIT_RECURSION=nnnn) at the start, the value is returned. The fourth -argument should point to an unsigned 32-bit integer. If no such value has been -set, the call to pcre_fullinfo() returns the error PCRE_ERROR_UNSET. -
- PCRE_INFO_SIZE --Return the size of the compiled pattern in bytes (for all three libraries). The -fourth argument should point to a size_t variable. This value does not -include the size of the pcre structure that is returned by -pcre_compile(). The value that is passed as the argument to -pcre_malloc() when pcre_compile() is getting memory in which to -place the compiled data is the value returned by this option plus the size of -the pcre structure. Studying a compiled pattern, with or without JIT, -does not alter the value returned by this option. -
- PCRE_INFO_STUDYSIZE --Return the size in bytes (for all three libraries) of the data block pointed to -by the study_data field in a pcre_extra block. If pcre_extra -is NULL, or there is no study data, zero is returned. The fourth argument -should point to a size_t variable. The study_data field is set by -pcre_study() to record information that will speed up matching (see the -section entitled -"Studying a pattern" -above). The format of the study_data block is private, but its length -is made available via this option so that it can be saved and restored (see the -pcreprecompile -documentation for details). -
- PCRE_INFO_REQUIREDCHARFLAGS --Returns 1 if there is a rightmost literal data unit that must exist in any -matched string, other than at its start. The fourth argument should point to -an int variable. If there is no such value, 0 is returned. If returning -1, the character value itself can be retrieved using PCRE_INFO_REQUIREDCHAR. - -
-For anchored patterns, a last literal value is recorded only if it follows -something of variable length. For example, for the pattern /^a\d+z\d+/ the -returned value 1 (with "z" returned from PCRE_INFO_REQUIREDCHAR), but for -/^a\dz\d/ the returned value is 0. -
- PCRE_INFO_REQUIREDCHAR --Return the value of the rightmost literal data unit that must exist in any -matched string, other than at its start, if such a value has been recorded. The -fourth argument should point to an uint32_t variable. If there is no such -value, 0 is returned. - -
-int pcre_refcount(pcre *code, int adjust); -
--The pcre_refcount() function is used to maintain a reference count in the -data block that contains a compiled pattern. It is provided for the benefit of -applications that operate in an object-oriented manner, where different parts -of the application may be using the same compiled pattern, but you want to free -the block when they are all done. -
--When a pattern is compiled, the reference count field is initialized to zero. -It is changed only by calling this function, whose action is to add the -adjust value (which may be positive or negative) to it. The yield of the -function is the new value. However, the value of the count is constrained to -lie between 0 and 65535, inclusive. If the new value is outside these limits, -it is forced to the appropriate limit value. -
--Except when it is zero, the reference count is not correctly preserved if a -pattern is compiled on one host and then transferred to a host whose byte-order -is different. (This seems a highly unlikely scenario.) -
--int pcre_exec(const pcre *code, const pcre_extra *extra, - const char *subject, int length, int startoffset, - int options, int *ovector, int ovecsize); -
--The function pcre_exec() is called to match a subject string against a -compiled pattern, which is passed in the code argument. If the -pattern was studied, the result of the study should be passed in the -extra argument. You can call pcre_exec() with the same code -and extra arguments as many times as you like, in order to match -different subject strings with the same pattern. -
--This function is the main matching facility of the library, and it operates in -a Perl-like manner. For specialist use there is also an alternative matching -function, which is described -below -in the section about the pcre_dfa_exec() function. -
--In most applications, the pattern will have been compiled (and optionally -studied) in the same process that calls pcre_exec(). However, it is -possible to save compiled patterns and study data, and then use them later -in different processes, possibly even on different hosts. For a discussion -about this, see the -pcreprecompile -documentation. -
--Here is an example of a simple call to pcre_exec(): -
- int rc; - int ovector[30]; - rc = pcre_exec( - re, /* result of pcre_compile() */ - NULL, /* we didn't study the pattern */ - "some string", /* the subject string */ - 11, /* the length of the subject string */ - 0, /* start at offset 0 in the subject */ - 0, /* default options */ - ovector, /* vector of integers for substring information */ - 30); /* number of elements (NOT size in bytes) */ -- -
-If the extra argument is not NULL, it must point to a pcre_extra -data block. The pcre_study() function returns such a block (when it -doesn't return NULL), but you can also create one for yourself, and pass -additional information in it. The pcre_extra block contains the following -fields (not necessarily in this order): -
- unsigned long int flags; - void *study_data; - void *executable_jit; - unsigned long int match_limit; - unsigned long int match_limit_recursion; - void *callout_data; - const unsigned char *tables; - unsigned char **mark; --In the 16-bit version of this structure, the mark field has type -"PCRE_UCHAR16 **". -
-The flags field is used to specify which of the other fields are set. The -flag bits are: -
- PCRE_EXTRA_CALLOUT_DATA - PCRE_EXTRA_EXECUTABLE_JIT - PCRE_EXTRA_MARK - PCRE_EXTRA_MATCH_LIMIT - PCRE_EXTRA_MATCH_LIMIT_RECURSION - PCRE_EXTRA_STUDY_DATA - PCRE_EXTRA_TABLES --Other flag bits should be set to zero. The study_data field and sometimes -the executable_jit field are set in the pcre_extra block that is -returned by pcre_study(), together with the appropriate flag bits. You -should not set these yourself, but you may add to the block by setting other -fields and their corresponding flag bits. - -
-The match_limit field provides a means of preventing PCRE from using up a -vast amount of resources when running patterns that are not going to match, -but which have a very large number of possibilities in their search trees. The -classic example is a pattern that uses nested unlimited repeats. -
--Internally, pcre_exec() uses a function called match(), which it -calls repeatedly (sometimes recursively). The limit set by match_limit is -imposed on the number of times this function is called during a match, which -has the effect of limiting the amount of backtracking that can take place. For -patterns that are not anchored, the count restarts from zero for each position -in the subject string. -
--When pcre_exec() is called with a pattern that was successfully studied -with a JIT option, the way that the matching is executed is entirely different. -However, there is still the possibility of runaway matching that goes on for a -very long time, and so the match_limit value is also used in this case -(but in a different way) to limit how long the matching can continue. -
--The default value for the limit can be set when PCRE is built; the default -default is 10 million, which handles all but the most extreme cases. You can -override the default by suppling pcre_exec() with a pcre_extra -block in which match_limit is set, and PCRE_EXTRA_MATCH_LIMIT is set in -the flags field. If the limit is exceeded, pcre_exec() returns -PCRE_ERROR_MATCHLIMIT. -
--A value for the match limit may also be supplied by an item at the start of a -pattern of the form -
- (*LIMIT_MATCH=d) --where d is a decimal number. However, such a setting is ignored unless d is -less than the limit set by the caller of pcre_exec() or, if no such limit -is set, less than the default. - -
-The match_limit_recursion field is similar to match_limit, but -instead of limiting the total number of times that match() is called, it -limits the depth of recursion. The recursion depth is a smaller number than the -total number of calls, because not all calls to match() are recursive. -This limit is of use only if it is set smaller than match_limit. -
--Limiting the recursion depth limits the amount of machine stack that can be -used, or, when PCRE has been compiled to use memory on the heap instead of the -stack, the amount of heap memory that can be used. This limit is not relevant, -and is ignored, when matching is done using JIT compiled code. -
--The default value for match_limit_recursion can be set when PCRE is -built; the default default is the same value as the default for -match_limit. You can override the default by suppling pcre_exec() -with a pcre_extra block in which match_limit_recursion is set, and -PCRE_EXTRA_MATCH_LIMIT_RECURSION is set in the flags field. If the limit -is exceeded, pcre_exec() returns PCRE_ERROR_RECURSIONLIMIT. -
--A value for the recursion limit may also be supplied by an item at the start of -a pattern of the form -
- (*LIMIT_RECURSION=d) --where d is a decimal number. However, such a setting is ignored unless d is -less than the limit set by the caller of pcre_exec() or, if no such limit -is set, less than the default. - -
-The callout_data field is used in conjunction with the "callout" feature, -and is described in the -pcrecallout -documentation. -
--The tables field is provided for use with patterns that have been -pre-compiled using custom character tables, saved to disc or elsewhere, and -then reloaded, because the tables that were used to compile a pattern are not -saved with it. See the -pcreprecompile -documentation for a discussion of saving compiled patterns for later use. If -NULL is passed using this mechanism, it forces PCRE's internal tables to be -used. -
--Warning: The tables that pcre_exec() uses must be the same as those -that were used when the pattern was compiled. If this is not the case, the -behaviour of pcre_exec() is undefined. Therefore, when a pattern is -compiled and matched in the same process, this field should never be set. In -this (the most common) case, the correct table pointer is automatically passed -with the compiled pattern from pcre_compile() to pcre_exec(). -
--If PCRE_EXTRA_MARK is set in the flags field, the mark field must -be set to point to a suitable variable. If the pattern contains any -backtracking control verbs such as (*MARK:NAME), and the execution ends up with -a name to pass back, a pointer to the name string (zero terminated) is placed -in the variable pointed to by the mark field. The names are within the -compiled pattern; if you wish to retain such a name you must copy it before -freeing the memory of a compiled pattern. If there is no name to pass back, the -variable pointed to by the mark field is set to NULL. For details of the -backtracking control verbs, see the section entitled -"Backtracking control" -in the -pcrepattern -documentation. -
--The unused bits of the options argument for pcre_exec() must be -zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx, -PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, -PCRE_NO_START_OPTIMIZE, PCRE_NO_UTF8_CHECK, PCRE_PARTIAL_HARD, and -PCRE_PARTIAL_SOFT. -
--If the pattern was successfully studied with one of the just-in-time (JIT) -compile options, the only supported options for JIT execution are -PCRE_NO_UTF8_CHECK, PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, -PCRE_NOTEMPTY_ATSTART, PCRE_PARTIAL_HARD, and PCRE_PARTIAL_SOFT. If an -unsupported option is used, JIT execution is disabled and the normal -interpretive code in pcre_exec() is run. -
- PCRE_ANCHORED --The PCRE_ANCHORED option limits pcre_exec() to matching at the first -matching position. If a pattern was compiled with PCRE_ANCHORED, or turned out -to be anchored by virtue of its contents, it cannot be made unachored at -matching time. -
- PCRE_BSR_ANYCRLF - PCRE_BSR_UNICODE --These options (which are mutually exclusive) control what the \R escape -sequence matches. The choice is either to match only CR, LF, or CRLF, or to -match any Unicode newline sequence. These options override the choice that was -made or defaulted when the pattern was compiled. -
- PCRE_NEWLINE_CR - PCRE_NEWLINE_LF - PCRE_NEWLINE_CRLF - PCRE_NEWLINE_ANYCRLF - PCRE_NEWLINE_ANY --These options override the newline definition that was chosen or defaulted when -the pattern was compiled. For details, see the description of -pcre_compile() above. During matching, the newline choice affects the -behaviour of the dot, circumflex, and dollar metacharacters. It may also alter -the way the match position is advanced after a match failure for an unanchored -pattern. - -
-When PCRE_NEWLINE_CRLF, PCRE_NEWLINE_ANYCRLF, or PCRE_NEWLINE_ANY is set, and a -match attempt for an unanchored pattern fails when the current position is at a -CRLF sequence, and the pattern contains no explicit matches for CR or LF -characters, the match position is advanced by two characters instead of one, in -other words, to after the CRLF. -
--The above rule is a compromise that makes the most common cases work as -expected. For example, if the pattern is .+A (and the PCRE_DOTALL option is not -set), it does not match the string "\r\nA" because, after failing at the -start, it skips both the CR and the LF before retrying. However, the pattern -[\r\n]A does match that string, because it contains an explicit CR or LF -reference, and so advances only by one character after the first failure. -
--An explicit match for CR of LF is either a literal appearance of one of those -characters, or one of the \r or \n escape sequences. Implicit matches such as -[^X] do not count, nor does \s (which includes CR and LF in the characters -that it matches). -
--Notwithstanding the above, anomalous effects may still occur when CRLF is a -valid newline sequence and explicit \r or \n escapes appear in the pattern. -
- PCRE_NOTBOL --This option specifies that first character of the subject string is not the -beginning of a line, so the circumflex metacharacter should not match before -it. Setting this without PCRE_MULTILINE (at compile time) causes circumflex -never to match. This option affects only the behaviour of the circumflex -metacharacter. It does not affect \A. -
- PCRE_NOTEOL --This option specifies that the end of the subject string is not the end of a -line, so the dollar metacharacter should not match it nor (except in multiline -mode) a newline immediately before it. Setting this without PCRE_MULTILINE (at -compile time) causes dollar never to match. This option affects only the -behaviour of the dollar metacharacter. It does not affect \Z or \z. -
- PCRE_NOTEMPTY --An empty string is not considered to be a valid match if this option is set. If -there are alternatives in the pattern, they are tried. If all the alternatives -match the empty string, the entire match fails. For example, if the pattern -
- a?b? --is applied to a string not beginning with "a" or "b", it matches an empty -string at the start of the subject. With PCRE_NOTEMPTY set, this match is not -valid, so PCRE searches further into the string for occurrences of "a" or "b". -
- PCRE_NOTEMPTY_ATSTART --This is like PCRE_NOTEMPTY, except that an empty string match that is not at -the start of the subject is permitted. If the pattern is anchored, such a match -can occur only if the pattern contains \K. - -
-Perl has no direct equivalent of PCRE_NOTEMPTY or PCRE_NOTEMPTY_ATSTART, but it -does make a special case of a pattern match of the empty string within its -split() function, and when using the /g modifier. It is possible to -emulate Perl's behaviour after matching a null string by first trying the match -again at the same offset with PCRE_NOTEMPTY_ATSTART and PCRE_ANCHORED, and then -if that fails, by advancing the starting offset (see below) and trying an -ordinary match again. There is some code that demonstrates how to do this in -the -pcredemo -sample program. In the most general case, you have to check to see if the -newline convention recognizes CRLF as a newline, and if so, and the current -character is CR followed by LF, advance the starting offset by two characters -instead of one. -
- PCRE_NO_START_OPTIMIZE --There are a number of optimizations that pcre_exec() uses at the start of -a match, in order to speed up the process. For example, if it is known that an -unanchored match must start with a specific character, it searches the subject -for that character, and fails immediately if it cannot find it, without -actually running the main matching function. This means that a special item -such as (*COMMIT) at the start of a pattern is not considered until after a -suitable starting point for the match has been found. Also, when callouts or -(*MARK) items are in use, these "start-up" optimizations can cause them to be -skipped if the pattern is never actually used. The start-up optimizations are -in effect a pre-scan of the subject that takes place before the pattern is run. - -
-The PCRE_NO_START_OPTIMIZE option disables the start-up optimizations, possibly -causing performance to suffer, but ensuring that in cases where the result is -"no match", the callouts do occur, and that items such as (*COMMIT) and (*MARK) -are considered at every possible starting position in the subject string. If -PCRE_NO_START_OPTIMIZE is set at compile time, it cannot be unset at matching -time. The use of PCRE_NO_START_OPTIMIZE at matching time (that is, passing it -to pcre_exec()) disables JIT execution; in this situation, matching is -always done using interpretively. -
--Setting PCRE_NO_START_OPTIMIZE can change the outcome of a matching operation. -Consider the pattern -
- (*COMMIT)ABC --When this is compiled, PCRE records the fact that a match must start with the -character "A". Suppose the subject string is "DEFABC". The start-up -optimization scans along the subject, finds "A" and runs the first match -attempt from there. The (*COMMIT) item means that the pattern must match the -current starting position, which in this case, it does. However, if the same -match is run with PCRE_NO_START_OPTIMIZE set, the initial scan along the -subject string does not happen. The first match attempt is run starting from -"D" and when this fails, (*COMMIT) prevents any further matches being tried, so -the overall result is "no match". If the pattern is studied, more start-up -optimizations may be used. For example, a minimum length for the subject may be -recorded. Consider the pattern -
- (*MARK:A)(X|Y) --The minimum length for a match is one character. If the subject is "ABC", there -will be attempts to match "ABC", "BC", "C", and then finally an empty string. -If the pattern is studied, the final attempt does not take place, because PCRE -knows that the subject is too short, and so the (*MARK) is never encountered. -In this case, studying the pattern does not affect the overall match result, -which is still "no match", but it does affect the auxiliary information that is -returned. -
- PCRE_NO_UTF8_CHECK --When PCRE_UTF8 is set at compile time, the validity of the subject as a UTF-8 -string is automatically checked when pcre_exec() is subsequently called. -The entire string is checked before any other processing takes place. The value -of startoffset is also checked to ensure that it points to the start of a -UTF-8 character. There is a discussion about the -validity of UTF-8 strings -in the -pcreunicode -page. If an invalid sequence of bytes is found, pcre_exec() returns the -error PCRE_ERROR_BADUTF8 or, if PCRE_PARTIAL_HARD is set and the problem is a -truncated character at the end of the subject, PCRE_ERROR_SHORTUTF8. In both -cases, information about the precise nature of the error may also be returned -(see the descriptions of these errors in the section entitled \fIError return -values from\fP pcre_exec() -below). -If startoffset contains a value that does not point to the start of a -UTF-8 character (or to the end of the subject), PCRE_ERROR_BADUTF8_OFFSET is -returned. - -
-If you already know that your subject is valid, and you want to skip these -checks for performance reasons, you can set the PCRE_NO_UTF8_CHECK option when -calling pcre_exec(). You might want to do this for the second and -subsequent calls to pcre_exec() if you are making repeated calls to find -all the matches in a single subject string. However, you should be sure that -the value of startoffset points to the start of a character (or the end -of the subject). When PCRE_NO_UTF8_CHECK is set, the effect of passing an -invalid string as a subject or an invalid value of startoffset is -undefined. Your program may crash or loop. -
- PCRE_PARTIAL_HARD - PCRE_PARTIAL_SOFT --These options turn on the partial matching feature. For backwards -compatibility, PCRE_PARTIAL is a synonym for PCRE_PARTIAL_SOFT. A partial match -occurs if the end of the subject string is reached successfully, but there are -not enough subject characters to complete the match. If this happens when -PCRE_PARTIAL_SOFT (but not PCRE_PARTIAL_HARD) is set, matching continues by -testing any remaining alternatives. Only if no complete match can be found is -PCRE_ERROR_PARTIAL returned instead of PCRE_ERROR_NOMATCH. In other words, -PCRE_PARTIAL_SOFT says that the caller is prepared to handle a partial match, -but only if no complete match can be found. - -
-If PCRE_PARTIAL_HARD is set, it overrides PCRE_PARTIAL_SOFT. In this case, if a -partial match is found, pcre_exec() immediately returns -PCRE_ERROR_PARTIAL, without considering any other alternatives. In other words, -when PCRE_PARTIAL_HARD is set, a partial match is considered to be more -important that an alternative complete match. -
--In both cases, the portion of the string that was inspected when the partial -match was found is set as the first matching string. There is a more detailed -discussion of partial and multi-segment matching, with examples, in the -pcrepartial -documentation. -
--The subject string is passed to pcre_exec() as a pointer in -subject, a length in length, and a starting offset in -startoffset. The units for length and startoffset are bytes -for the 8-bit library, 16-bit data items for the 16-bit library, and 32-bit -data items for the 32-bit library. -
--If startoffset is negative or greater than the length of the subject, -pcre_exec() returns PCRE_ERROR_BADOFFSET. When the starting offset is -zero, the search for a match starts at the beginning of the subject, and this -is by far the most common case. In UTF-8 or UTF-16 mode, the offset must point -to the start of a character, or the end of the subject (in UTF-32 mode, one -data unit equals one character, so all offsets are valid). Unlike the pattern -string, the subject may contain binary zeroes. -
--A non-zero starting offset is useful when searching for another match in the -same subject by calling pcre_exec() again after a previous success. -Setting startoffset differs from just passing over a shortened string and -setting PCRE_NOTBOL in the case of a pattern that begins with any kind of -lookbehind. For example, consider the pattern -
- \Biss\B --which finds occurrences of "iss" in the middle of words. (\B matches only if -the current position in the subject is not a word boundary.) When applied to -the string "Mississipi" the first call to pcre_exec() finds the first -occurrence. If pcre_exec() is called again with just the remainder of the -subject, namely "issipi", it does not match, because \B is always false at the -start of the subject, which is deemed to be a word boundary. However, if -pcre_exec() is passed the entire string again, but with startoffset -set to 4, it finds the second occurrence of "iss" because it is able to look -behind the starting point to discover that it is preceded by a letter. - -
-Finding all the matches in a subject is tricky when the pattern can match an -empty string. It is possible to emulate Perl's /g behaviour by first trying the -match again at the same offset, with the PCRE_NOTEMPTY_ATSTART and -PCRE_ANCHORED options, and then if that fails, advancing the starting offset -and trying an ordinary match again. There is some code that demonstrates how to -do this in the -pcredemo -sample program. In the most general case, you have to check to see if the -newline convention recognizes CRLF as a newline, and if so, and the current -character is CR followed by LF, advance the starting offset by two characters -instead of one. -
--If a non-zero starting offset is passed when the pattern is anchored, one -attempt to match at the given offset is made. This can only succeed if the -pattern does not require the match to be at the start of the subject. -
--In general, a pattern matches a certain portion of the subject, and in -addition, further substrings from the subject may be picked out by parts of the -pattern. Following the usage in Jeffrey Friedl's book, this is called -"capturing" in what follows, and the phrase "capturing subpattern" is used for -a fragment of a pattern that picks out a substring. PCRE supports several other -kinds of parenthesized subpattern that do not cause substrings to be captured. -
--Captured substrings are returned to the caller via a vector of integers whose -address is passed in ovector. The number of elements in the vector is -passed in ovecsize, which must be a non-negative number. Note: this -argument is NOT the size of ovector in bytes. -
--The first two-thirds of the vector is used to pass back captured substrings, -each substring using a pair of integers. The remaining third of the vector is -used as workspace by pcre_exec() while matching capturing subpatterns, -and is not available for passing back information. The number passed in -ovecsize should always be a multiple of three. If it is not, it is -rounded down. -
--When a match is successful, information about captured substrings is returned -in pairs of integers, starting at the beginning of ovector, and -continuing up to two-thirds of its length at the most. The first element of -each pair is set to the offset of the first character in a substring, and the -second is set to the offset of the first character after the end of a -substring. These values are always data unit offsets, even in UTF mode. They -are byte offsets in the 8-bit library, 16-bit data item offsets in the 16-bit -library, and 32-bit data item offsets in the 32-bit library. Note: they -are not character counts. -
--The first pair of integers, ovector[0] and ovector[1], identify the -portion of the subject string matched by the entire pattern. The next pair is -used for the first capturing subpattern, and so on. The value returned by -pcre_exec() is one more than the highest numbered pair that has been set. -For example, if two substrings have been captured, the returned value is 3. If -there are no capturing subpatterns, the return value from a successful match is -1, indicating that just the first pair of offsets has been set. -
--If a capturing subpattern is matched repeatedly, it is the last portion of the -string that it matched that is returned. -
--If the vector is too small to hold all the captured substring offsets, it is -used as far as possible (up to two-thirds of its length), and the function -returns a value of zero. If neither the actual string matched nor any captured -substrings are of interest, pcre_exec() may be called with ovector -passed as NULL and ovecsize as zero. However, if the pattern contains -back references and the ovector is not big enough to remember the related -substrings, PCRE has to get additional memory for use during matching. Thus it -is usually advisable to supply an ovector of reasonable size. -
--There are some cases where zero is returned (indicating vector overflow) when -in fact the vector is exactly the right size for the final match. For example, -consider the pattern -
- (a)(?:(b)c|bd) --If a vector of 6 elements (allowing for only 1 captured substring) is given -with subject string "abd", pcre_exec() will try to set the second -captured string, thereby recording a vector overflow, before failing to match -"c" and backing up to try the second alternative. The zero return, however, -does correctly indicate that the maximum number of slots (namely 2) have been -filled. In similar cases where there is temporary overflow, but the final -number of used slots is actually less than the maximum, a non-zero value is -returned. - -
-The pcre_fullinfo() function can be used to find out how many capturing -subpatterns there are in a compiled pattern. The smallest size for -ovector that will allow for n captured substrings, in addition to -the offsets of the substring matched by the whole pattern, is (n+1)*3. -
--It is possible for capturing subpattern number n+1 to match some part of -the subject when subpattern n has not been used at all. For example, if -the string "abc" is matched against the pattern (a|(z))(bc) the return from the -function is 4, and subpatterns 1 and 3 are matched, but 2 is not. When this -happens, both values in the offset pairs corresponding to unused subpatterns -are set to -1. -
--Offset values that correspond to unused subpatterns at the end of the -expression are also set to -1. For example, if the string "abc" is matched -against the pattern (abc)(x(yz)?)? subpatterns 2 and 3 are not matched. The -return from the function is 2, because the highest used capturing subpattern -number is 1, and the offsets for for the second and third capturing subpatterns -(assuming the vector is large enough, of course) are set to -1. -
--Note: Elements in the first two-thirds of ovector that do not -correspond to capturing parentheses in the pattern are never changed. That is, -if a pattern contains n capturing parentheses, no more than -ovector[0] to ovector[2n+1] are set by pcre_exec(). The other -elements (in the first two-thirds) retain whatever values they previously had. -
--Some convenience functions are provided for extracting the captured substrings -as separate strings. These are described below. -
--If pcre_exec() fails, it returns a negative number. The following are -defined in the header file: -
- PCRE_ERROR_NOMATCH (-1) --The subject string did not match the pattern. -
- PCRE_ERROR_NULL (-2) --Either code or subject was passed as NULL, or ovector was -NULL and ovecsize was not zero. -
- PCRE_ERROR_BADOPTION (-3) --An unrecognized bit was set in the options argument. -
- PCRE_ERROR_BADMAGIC (-4) --PCRE stores a 4-byte "magic number" at the start of the compiled code, to catch -the case when it is passed a junk pointer and to detect when a pattern that was -compiled in an environment of one endianness is run in an environment with the -other endianness. This is the error that PCRE gives when the magic number is -not present. -
- PCRE_ERROR_UNKNOWN_OPCODE (-5) --While running the pattern match, an unknown item was encountered in the -compiled pattern. This error could be caused by a bug in PCRE or by overwriting -of the compiled pattern. -
- PCRE_ERROR_NOMEMORY (-6) --If a pattern contains back references, but the ovector that is passed to -pcre_exec() is not big enough to remember the referenced substrings, PCRE -gets a block of memory at the start of matching to use for this purpose. If the -call via pcre_malloc() fails, this error is given. The memory is -automatically freed at the end of matching. - -
-This error is also given if pcre_stack_malloc() fails in -pcre_exec(). This can happen only when PCRE has been compiled with ---disable-stack-for-recursion. -
- PCRE_ERROR_NOSUBSTRING (-7) --This error is used by the pcre_copy_substring(), -pcre_get_substring(), and pcre_get_substring_list() functions (see -below). It is never returned by pcre_exec(). -
- PCRE_ERROR_MATCHLIMIT (-8) --The backtracking limit, as specified by the match_limit field in a -pcre_extra structure (or defaulted) was reached. See the description -above. -
- PCRE_ERROR_CALLOUT (-9) --This error is never generated by pcre_exec() itself. It is provided for -use by callout functions that want to yield a distinctive error code. See the -pcrecallout -documentation for details. -
- PCRE_ERROR_BADUTF8 (-10) --A string that contains an invalid UTF-8 byte sequence was passed as a subject, -and the PCRE_NO_UTF8_CHECK option was not set. If the size of the output vector -(ovecsize) is at least 2, the byte offset to the start of the the invalid -UTF-8 character is placed in the first element, and a reason code is placed in -the second element. The reason codes are listed in the -following section. -For backward compatibility, if PCRE_PARTIAL_HARD is set and the problem is a -truncated UTF-8 character at the end of the subject (reason codes 1 to 5), -PCRE_ERROR_SHORTUTF8 is returned instead of PCRE_ERROR_BADUTF8. -
- PCRE_ERROR_BADUTF8_OFFSET (-11) --The UTF-8 byte sequence that was passed as a subject was checked and found to -be valid (the PCRE_NO_UTF8_CHECK option was not set), but the value of -startoffset did not point to the beginning of a UTF-8 character or the -end of the subject. -
- PCRE_ERROR_PARTIAL (-12) --The subject string did not match, but it did match partially. See the -pcrepartial -documentation for details of partial matching. -
- PCRE_ERROR_BADPARTIAL (-13) --This code is no longer in use. It was formerly returned when the PCRE_PARTIAL -option was used with a compiled pattern containing items that were not -supported for partial matching. From release 8.00 onwards, there are no -restrictions on partial matching. -
- PCRE_ERROR_INTERNAL (-14) --An unexpected internal error has occurred. This error could be caused by a bug -in PCRE or by overwriting of the compiled pattern. -
- PCRE_ERROR_BADCOUNT (-15) --This error is given if the value of the ovecsize argument is negative. -
- PCRE_ERROR_RECURSIONLIMIT (-21) --The internal recursion limit, as specified by the match_limit_recursion -field in a pcre_extra structure (or defaulted) was reached. See the -description above. -
- PCRE_ERROR_BADNEWLINE (-23) --An invalid combination of PCRE_NEWLINE_xxx options was given. -
- PCRE_ERROR_BADOFFSET (-24) --The value of startoffset was negative or greater than the length of the -subject, that is, the value in length. -
- PCRE_ERROR_SHORTUTF8 (-25) --This error is returned instead of PCRE_ERROR_BADUTF8 when the subject string -ends with a truncated UTF-8 character and the PCRE_PARTIAL_HARD option is set. -Information about the failure is returned as for PCRE_ERROR_BADUTF8. It is in -fact sufficient to detect this case, but this special error code for -PCRE_PARTIAL_HARD precedes the implementation of returned information; it is -retained for backwards compatibility. -
- PCRE_ERROR_RECURSELOOP (-26) --This error is returned when pcre_exec() detects a recursion loop within -the pattern. Specifically, it means that either the whole pattern or a -subpattern has been called recursively for the second time at the same position -in the subject string. Some simple patterns that might do this are detected and -faulted at compile time, but more complicated cases, in particular mutual -recursions between two different subpatterns, cannot be detected until run -time. -
- PCRE_ERROR_JIT_STACKLIMIT (-27) --This error is returned when a pattern that was successfully studied using a -JIT compile option is being matched, but the memory available for the -just-in-time processing stack is not large enough. See the -pcrejit -documentation for more details. -
- PCRE_ERROR_BADMODE (-28) --This error is given if a pattern that was compiled by the 8-bit library is -passed to a 16-bit or 32-bit library function, or vice versa. -
- PCRE_ERROR_BADENDIANNESS (-29) --This error is given if a pattern that was compiled and saved is reloaded on a -host with different endianness. The utility function -pcre_pattern_to_host_byte_order() can be used to convert such a pattern -so that it runs on the new host. -
- PCRE_ERROR_JIT_BADOPTION --This error is returned when a pattern that was successfully studied using a JIT -compile option is being matched, but the matching mode (partial or complete -match) does not correspond to any JIT compilation mode. When the JIT fast path -function is used, this error may be also given for invalid options. See the -pcrejit -documentation for more details. -
- PCRE_ERROR_BADLENGTH (-32) --This error is given if pcre_exec() is called with a negative value for -the length argument. - -
-Error numbers -16 to -20, -22, and 30 are not used by pcre_exec(). -
--This section applies only to the 8-bit library. The corresponding information -for the 16-bit and 32-bit libraries is given in the -pcre16 -and -pcre32 -pages. -
--When pcre_exec() returns either PCRE_ERROR_BADUTF8 or -PCRE_ERROR_SHORTUTF8, and the size of the output vector (ovecsize) is at -least 2, the offset of the start of the invalid UTF-8 character is placed in -the first output vector element (ovector[0]) and a reason code is placed -in the second element (ovector[1]). The reason codes are given names in -the pcre.h header file: -
- PCRE_UTF8_ERR1 - PCRE_UTF8_ERR2 - PCRE_UTF8_ERR3 - PCRE_UTF8_ERR4 - PCRE_UTF8_ERR5 --The string ends with a truncated UTF-8 character; the code specifies how many -bytes are missing (1 to 5). Although RFC 3629 restricts UTF-8 characters to be -no longer than 4 bytes, the encoding scheme (originally defined by RFC 2279) -allows for up to 6 bytes, and this is checked first; hence the possibility of -4 or 5 missing bytes. -
- PCRE_UTF8_ERR6 - PCRE_UTF8_ERR7 - PCRE_UTF8_ERR8 - PCRE_UTF8_ERR9 - PCRE_UTF8_ERR10 --The two most significant bits of the 2nd, 3rd, 4th, 5th, or 6th byte of the -character do not have the binary value 0b10 (that is, either the most -significant bit is 0, or the next bit is 1). -
- PCRE_UTF8_ERR11 - PCRE_UTF8_ERR12 --A character that is valid by the RFC 2279 rules is either 5 or 6 bytes long; -these code points are excluded by RFC 3629. -
- PCRE_UTF8_ERR13 --A 4-byte character has a value greater than 0x10fff; these code points are -excluded by RFC 3629. -
- PCRE_UTF8_ERR14 --A 3-byte character has a value in the range 0xd800 to 0xdfff; this range of -code points are reserved by RFC 3629 for use with UTF-16, and so are excluded -from UTF-8. -
- PCRE_UTF8_ERR15 - PCRE_UTF8_ERR16 - PCRE_UTF8_ERR17 - PCRE_UTF8_ERR18 - PCRE_UTF8_ERR19 --A 2-, 3-, 4-, 5-, or 6-byte character is "overlong", that is, it codes for a -value that can be represented by fewer bytes, which is invalid. For example, -the two bytes 0xc0, 0xae give the value 0x2e, whose correct coding uses just -one byte. -
- PCRE_UTF8_ERR20 --The two most significant bits of the first byte of a character have the binary -value 0b10 (that is, the most significant bit is 1 and the second is 0). Such a -byte can only validly occur as the second or subsequent byte of a multi-byte -character. -
- PCRE_UTF8_ERR21 --The first byte of a character has the value 0xfe or 0xff. These values can -never occur in a valid UTF-8 string. -
- PCRE_UTF8_ERR22 --This error code was formerly used when the presence of a so-called -"non-character" caused an error. Unicode corrigendum #9 makes it clear that -such characters should not cause a string to be rejected, and so this code is -no longer in use and is never returned. - -
-int pcre_copy_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber, char *buffer,
- int buffersize);
-
-
-int pcre_get_substring(const char *subject, int *ovector,
- int stringcount, int stringnumber,
- const char **stringptr);
-
-
-int pcre_get_substring_list(const char *subject,
- int *ovector, int stringcount, const char ***listptr);
-
-Captured substrings can be accessed directly by using the offsets returned by -pcre_exec() in ovector. For convenience, the functions -pcre_copy_substring(), pcre_get_substring(), and -pcre_get_substring_list() are provided for extracting captured substrings -as new, separate, zero-terminated strings. These functions identify substrings -by number. The next section describes functions for extracting named -substrings. -
--A substring that contains a binary zero is correctly extracted and has a -further zero added on the end, but the result is not, of course, a C string. -However, you can process such a string by referring to the length that is -returned by pcre_copy_substring() and pcre_get_substring(). -Unfortunately, the interface to pcre_get_substring_list() is not adequate -for handling strings containing binary zeros, because the end of the final -string is not independently indicated. -
--The first three arguments are the same for all three of these functions: -subject is the subject string that has just been successfully matched, -ovector is a pointer to the vector of integer offsets that was passed to -pcre_exec(), and stringcount is the number of substrings that were -captured by the match, including the substring that matched the entire regular -expression. This is the value returned by pcre_exec() if it is greater -than zero. If pcre_exec() returned zero, indicating that it ran out of -space in ovector, the value passed as stringcount should be the -number of elements in the vector divided by three. -
--The functions pcre_copy_substring() and pcre_get_substring() -extract a single substring, whose number is given as stringnumber. A -value of zero extracts the substring that matched the entire pattern, whereas -higher values extract the captured substrings. For pcre_copy_substring(), -the string is placed in buffer, whose length is given by -buffersize, while for pcre_get_substring() a new block of memory is -obtained via pcre_malloc, and its address is returned via -stringptr. The yield of the function is the length of the string, not -including the terminating zero, or one of these error codes: -
- PCRE_ERROR_NOMEMORY (-6) --The buffer was too small for pcre_copy_substring(), or the attempt to get -memory failed for pcre_get_substring(). -
- PCRE_ERROR_NOSUBSTRING (-7) --There is no substring whose number is stringnumber. - -
-The pcre_get_substring_list() function extracts all available substrings -and builds a list of pointers to them. All this is done in a single block of -memory that is obtained via pcre_malloc. The address of the memory block -is returned via listptr, which is also the start of the list of string -pointers. The end of the list is marked by a NULL pointer. The yield of the -function is zero if all went well, or the error code -
- PCRE_ERROR_NOMEMORY (-6) --if the attempt to get the memory block failed. - -
-When any of these functions encounter a substring that is unset, which can -happen when capturing subpattern number n+1 matches some part of the -subject, but subpattern n has not been used at all, they return an empty -string. This can be distinguished from a genuine zero-length substring by -inspecting the appropriate offset in ovector, which is negative for unset -substrings. -
--The two convenience functions pcre_free_substring() and -pcre_free_substring_list() can be used to free the memory returned by -a previous call of pcre_get_substring() or -pcre_get_substring_list(), respectively. They do nothing more than call -the function pointed to by pcre_free, which of course could be called -directly from a C program. However, PCRE is used in some situations where it is -linked via a special interface to another programming language that cannot use -pcre_free directly; it is for these cases that the functions are -provided. -
-
-int pcre_get_stringnumber(const pcre *code,
- const char *name);
-
-
-int pcre_copy_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- char *buffer, int buffersize);
-
-
-int pcre_get_named_substring(const pcre *code,
- const char *subject, int *ovector,
- int stringcount, const char *stringname,
- const char **stringptr);
-
-To extract a substring by name, you first have to find associated number. -For example, for this pattern -
- (a+)b(?<xxx>\d+)... --the number of the subpattern called "xxx" is 2. If the name is known to be -unique (PCRE_DUPNAMES was not set), you can find the number from the name by -calling pcre_get_stringnumber(). The first argument is the compiled -pattern, and the second is the name. The yield of the function is the -subpattern number, or PCRE_ERROR_NOSUBSTRING (-7) if there is no subpattern of -that name. - -
-Given the number, you can extract the substring directly, or use one of the -functions described in the previous section. For convenience, there are also -two functions that do the whole job. -
--Most of the arguments of pcre_copy_named_substring() and -pcre_get_named_substring() are the same as those for the similarly named -functions that extract by number. As these are described in the previous -section, they are not re-described here. There are just two differences: -
--First, instead of a substring number, a substring name is given. Second, there -is an extra argument, given at the start, which is a pointer to the compiled -pattern. This is needed in order to gain access to the name-to-number -translation table. -
--These functions call pcre_get_stringnumber(), and if it succeeds, they -then call pcre_copy_substring() or pcre_get_substring(), as -appropriate. NOTE: If PCRE_DUPNAMES is set and there are duplicate names, -the behaviour may not be what you want (see the next section). -
--Warning: If the pattern uses the (?| feature to set up multiple -subpatterns with the same number, as described in the -section on duplicate subpattern numbers -in the -pcrepattern -page, you cannot use names to distinguish the different subpatterns, because -names are not included in the compiled code. The matching process uses only -numbers. For this reason, the use of different names for subpatterns of the -same number causes an error at compile time. -
--int pcre_get_stringtable_entries(const pcre *code, - const char *name, char **first, char **last); -
--When a pattern is compiled with the PCRE_DUPNAMES option, names for subpatterns -are not required to be unique. (Duplicate names are always allowed for -subpatterns with the same number, created by using the (?| feature. Indeed, if -such subpatterns are named, they are required to use the same names.) -
--Normally, patterns with duplicate names are such that in any one match, only -one of the named subpatterns participates. An example is shown in the -pcrepattern -documentation. -
--When duplicates are present, pcre_copy_named_substring() and -pcre_get_named_substring() return the first substring corresponding to -the given name that is set. If none are set, PCRE_ERROR_NOSUBSTRING (-7) is -returned; no data is returned. The pcre_get_stringnumber() function -returns one of the numbers that are associated with the name, but it is not -defined which it is. -
--If you want to get full details of all captured substrings for a given name, -you must use the pcre_get_stringtable_entries() function. The first -argument is the compiled pattern, and the second is the name. The third and -fourth are pointers to variables which are updated by the function. After it -has run, they point to the first and last entries in the name-to-number table -for the given name. The function itself returns the length of each entry, or -PCRE_ERROR_NOSUBSTRING (-7) if there are none. The format of the table is -described above in the section entitled Information about a pattern -above. -Given all the relevant entries for the name, you can extract each of their -numbers, and hence the captured data, if any. -
--The traditional matching function uses a similar algorithm to Perl, which stops -when it finds the first match, starting at a given point in the subject. If you -want to find all possible matches, or the longest possible match, consider -using the alternative matching function (see below) instead. If you cannot use -the alternative function, but still need to find all possible matches, you -can kludge it up by making use of the callout facility, which is described in -the -pcrecallout -documentation. -
--What you have to do is to insert a callout right at the end of the pattern. -When your callout function is called, extract and save the current matched -substring. Then return 1, which forces pcre_exec() to backtrack and try -other alternatives. Ultimately, when it runs out of matches, pcre_exec() -will yield PCRE_ERROR_NOMATCH. -
--Matching certain patterns using pcre_exec() can use a lot of process -stack, which in certain environments can be rather limited in size. Some users -find it helpful to have an estimate of the amount of stack that is used by -pcre_exec(), to help them set recursion limits, as described in the -pcrestack -documentation. The estimate that is output by pcretest when called with -the -m and -C options is obtained by calling pcre_exec with -the values NULL, NULL, NULL, -999, and -999 for its first five arguments. -
--Normally, if its first argument is NULL, pcre_exec() immediately returns -the negative error code PCRE_ERROR_NULL, but with this special combination of -arguments, it returns instead a negative number whose absolute value is the -approximate stack frame size in bytes. (A negative number is used so that it is -clear that no match has happened.) The value is approximate because in some -cases, recursive calls to pcre_exec() occur when there are one or two -additional variables on the stack. -
--If PCRE has been compiled to use the heap instead of the stack for recursion, -the value returned is the size of each block that is obtained from the heap. -
--int pcre_dfa_exec(const pcre *code, const pcre_extra *extra, - const char *subject, int length, int startoffset, - int options, int *ovector, int ovecsize, - int *workspace, int wscount); -
--The function pcre_dfa_exec() is called to match a subject string against -a compiled pattern, using a matching algorithm that scans the subject string -just once, and does not backtrack. This has different characteristics to the -normal algorithm, and is not compatible with Perl. Some of the features of PCRE -patterns are not supported. Nevertheless, there are times when this kind of -matching can be useful. For a discussion of the two matching algorithms, and a -list of features that pcre_dfa_exec() does not support, see the -pcrematching -documentation. -
--The arguments for the pcre_dfa_exec() function are the same as for -pcre_exec(), plus two extras. The ovector argument is used in a -different way, and this is described below. The other common arguments are used -in the same way as for pcre_exec(), so their description is not repeated -here. -
--The two additional arguments provide workspace for the function. The workspace -vector should contain at least 20 elements. It is used for keeping track of -multiple paths through the pattern tree. More workspace will be needed for -patterns and subjects where there are a lot of potential matches. -
--Here is an example of a simple call to pcre_dfa_exec(): -
- int rc; - int ovector[10]; - int wspace[20]; - rc = pcre_dfa_exec( - re, /* result of pcre_compile() */ - NULL, /* we didn't study the pattern */ - "some string", /* the subject string */ - 11, /* the length of the subject string */ - 0, /* start at offset 0 in the subject */ - 0, /* default options */ - ovector, /* vector of integers for substring information */ - 10, /* number of elements (NOT size in bytes) */ - wspace, /* working space vector */ - 20); /* number of elements (NOT size in bytes) */ -- -
-The unused bits of the options argument for pcre_dfa_exec() must be -zero. The only bits that may be set are PCRE_ANCHORED, PCRE_NEWLINE_xxx, -PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, -PCRE_NO_UTF8_CHECK, PCRE_BSR_ANYCRLF, PCRE_BSR_UNICODE, PCRE_NO_START_OPTIMIZE, -PCRE_PARTIAL_HARD, PCRE_PARTIAL_SOFT, PCRE_DFA_SHORTEST, and PCRE_DFA_RESTART. -All but the last four of these are exactly the same as for pcre_exec(), -so their description is not repeated here. -
- PCRE_PARTIAL_HARD - PCRE_PARTIAL_SOFT --These have the same general effect as they do for pcre_exec(), but the -details are slightly different. When PCRE_PARTIAL_HARD is set for -pcre_dfa_exec(), it returns PCRE_ERROR_PARTIAL if the end of the subject -is reached and there is still at least one matching possibility that requires -additional characters. This happens even if some complete matches have also -been found. When PCRE_PARTIAL_SOFT is set, the return code PCRE_ERROR_NOMATCH -is converted into PCRE_ERROR_PARTIAL if the end of the subject is reached, -there have been no complete matches, but there is still at least one matching -possibility. The portion of the string that was inspected when the longest -partial match was found is set as the first matching string in both cases. -There is a more detailed discussion of partial and multi-segment matching, with -examples, in the -pcrepartial -documentation. -
- PCRE_DFA_SHORTEST --Setting the PCRE_DFA_SHORTEST option causes the matching algorithm to stop as -soon as it has found one match. Because of the way the alternative algorithm -works, this is necessarily the shortest possible match at the first possible -matching point in the subject string. -
- PCRE_DFA_RESTART --When pcre_dfa_exec() returns a partial match, it is possible to call it -again, with additional subject characters, and have it continue with the same -match. The PCRE_DFA_RESTART option requests this action; when it is set, the -workspace and wscount options must reference the same vector as -before because data about the match so far is left in them after a partial -match. There is more discussion of this facility in the -pcrepartial -documentation. - -
-When pcre_dfa_exec() succeeds, it may have matched more than one -substring in the subject. Note, however, that all the matches from one run of -the function start at the same point in the subject. The shorter matches are -all initial substrings of the longer matches. For example, if the pattern -
- <.*> --is matched against the string -
- This is <something> <something else> <something further> no more --the three matched strings are -
- <something> - <something> <something else> - <something> <something else> <something further> --On success, the yield of the function is a number greater than zero, which is -the number of matched substrings. The substrings themselves are returned in -ovector. Each string uses two elements; the first is the offset to the -start, and the second is the offset to the end. In fact, all the strings have -the same start offset. (Space could have been saved by giving this only once, -but it was decided to retain some compatibility with the way pcre_exec() -returns data, even though the meaning of the strings is different.) - -
-The strings are returned in reverse order of length; that is, the longest -matching string is given first. If there were too many matches to fit into -ovector, the yield of the function is zero, and the vector is filled with -the longest matches. Unlike pcre_exec(), pcre_dfa_exec() can use -the entire ovector for returning matched strings. -
--NOTE: PCRE's "auto-possessification" optimization usually applies to character -repeats at the end of a pattern (as well as internally). For example, the -pattern "a\d+" is compiled as if it were "a\d++" because there is no point -even considering the possibility of backtracking into the repeated digits. For -DFA matching, this means that only one possible match is found. If you really -do want multiple matches in such cases, either use an ungreedy repeat -("a\d+?") or set the PCRE_NO_AUTO_POSSESS option when compiling. -
--The pcre_dfa_exec() function returns a negative number when it fails. -Many of the errors are the same as for pcre_exec(), and these are -described -above. -There are in addition the following errors that are specific to -pcre_dfa_exec(): -
- PCRE_ERROR_DFA_UITEM (-16) --This return is given if pcre_dfa_exec() encounters an item in the pattern -that it does not support, for instance, the use of \C or a back reference. -
- PCRE_ERROR_DFA_UCOND (-17) --This return is given if pcre_dfa_exec() encounters a condition item that -uses a back reference for the condition, or a test for recursion in a specific -group. These are not supported. -
- PCRE_ERROR_DFA_UMLIMIT (-18) --This return is given if pcre_dfa_exec() is called with an extra -block that contains a setting of the match_limit or -match_limit_recursion fields. This is not supported (these fields are -meaningless for DFA matching). -
- PCRE_ERROR_DFA_WSSIZE (-19) --This return is given if pcre_dfa_exec() runs out of space in the -workspace vector. -
- PCRE_ERROR_DFA_RECURSE (-20) --When a recursive subpattern is processed, the matching function calls itself -recursively, using private vectors for ovector and workspace. This -error is given if the output vector is not large enough. This should be -extremely rare, as a vector of size 1000 is used. -
- PCRE_ERROR_DFA_BADRESTART (-30) --When pcre_dfa_exec() is called with the PCRE_DFA_RESTART option, -some plausibility checks are made on the contents of the workspace, which -should contain data about the previous partial match. If any of these checks -fail, this error is given. - -
-pcre16(3), pcre32(3), pcrebuild(3), pcrecallout(3), -pcrecpp(3)(3), pcrematching(3), pcrepartial(3), -pcreposix(3), pcreprecompile(3), pcresample(3), -pcrestack(3). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 18 December 2015
-
-Copyright © 1997-2015 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrebuild.html b/libs/Pcre16/docs/doc/html/pcrebuild.html deleted file mode 100644 index 03c8cbe0b2..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrebuild.html +++ /dev/null @@ -1,534 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-PCRE is distributed with a configure script that can be used to build the -library in Unix-like environments using the applications known as Autotools. -Also in the distribution are files to support building using CMake -instead of configure. The text file -README -contains general information about building with Autotools (some of which is -repeated below), and also has some comments about building on various operating -systems. There is a lot more information about building PCRE without using -Autotools (including information about using CMake and building "by -hand") in the text file called -NON-AUTOTOOLS-BUILD. -You should consult this file as well as the -README -file if you are building in a non-Unix-like environment. -
--The rest of this document describes the optional features of PCRE that can be -selected when the library is compiled. It assumes use of the configure -script, where the optional features are selected or deselected by providing -options to configure before running the make command. However, the -same options can be selected in both Unix-like and non-Unix-like environments -using the GUI facility of cmake-gui if you are using CMake instead -of configure to build PCRE. -
--If you are not using Autotools or CMake, option selection can be done by -editing the config.h file, or by passing parameter settings to the -compiler, as described in -NON-AUTOTOOLS-BUILD. -
--The complete list of options for configure (which includes the standard -ones such as the selection of the installation directory) can be obtained by -running -
- ./configure --help --The following sections include descriptions of options whose names begin with ---enable or --disable. These settings specify changes to the defaults for the -configure command. Because of the way that configure works, ---enable and --disable always come in pairs, so the complementary option always -exists as well, but as it specifies the default, it is not described. - -
-By default, a library called libpcre is built, containing functions that -take string arguments contained in vectors of bytes, either as single-byte -characters, or interpreted as UTF-8 strings. You can also build a separate -library, called libpcre16, in which strings are contained in vectors of -16-bit data units and interpreted either as single-unit characters or UTF-16 -strings, by adding -
- --enable-pcre16 --to the configure command. You can also build yet another separate -library, called libpcre32, in which strings are contained in vectors of -32-bit data units and interpreted either as single-unit characters or UTF-32 -strings, by adding -
- --enable-pcre32 --to the configure command. If you do not want the 8-bit library, add -
- --disable-pcre8 --as well. At least one of the three libraries must be built. Note that the C++ -and POSIX wrappers are for the 8-bit library only, and that pcregrep is -an 8-bit program. None of these are built if you select only the 16-bit or -32-bit libraries. - -
-The Autotools PCRE building process uses libtool to build both shared and -static libraries by default. You can suppress one of these by adding one of -
- --disable-shared - --disable-static --to the configure command, as required. - -
-By default, if the 8-bit library is being built, the configure script -will search for a C++ compiler and C++ header files. If it finds them, it -automatically builds the C++ wrapper library (which supports only 8-bit -strings). You can disable this by adding -
- --disable-cpp --to the configure command. - -
-To build PCRE with support for UTF Unicode character strings, add -
- --enable-utf --to the configure command. This setting applies to all three libraries, -adding support for UTF-8 to the 8-bit library, support for UTF-16 to the 16-bit -library, and support for UTF-32 to the to the 32-bit library. There are no -separate options for enabling UTF-8, UTF-16 and UTF-32 independently because -that would allow ridiculous settings such as requesting UTF-16 support while -building only the 8-bit library. It is not possible to build one library with -UTF support and another without in the same configuration. (For backwards -compatibility, --enable-utf8 is a synonym of --enable-utf.) - -
-Of itself, this setting does not make PCRE treat strings as UTF-8, UTF-16 or -UTF-32. As well as compiling PCRE with this option, you also have have to set -the PCRE_UTF8, PCRE_UTF16 or PCRE_UTF32 option (as appropriate) when you call -one of the pattern compiling functions. -
--If you set --enable-utf when compiling in an EBCDIC environment, PCRE expects -its input to be either ASCII or UTF-8 (depending on the run-time option). It is -not possible to support both EBCDIC and UTF-8 codes in the same version of the -library. Consequently, --enable-utf and --enable-ebcdic are mutually -exclusive. -
--UTF support allows the libraries to process character codepoints up to 0x10ffff -in the strings that they handle. On its own, however, it does not provide any -facilities for accessing the properties of such characters. If you want to be -able to use the pattern escapes \P, \p, and \X, which refer to Unicode -character properties, you must add -
- --enable-unicode-properties --to the configure command. This implies UTF support, even if you have -not explicitly requested it. - -
-Including Unicode property support adds around 30K of tables to the PCRE -library. Only the general category properties such as Lu and Nd are -supported. Details are given in the -pcrepattern -documentation. -
--Just-in-time compiler support is included in the build by specifying -
- --enable-jit --This support is available only for certain hardware architectures. If this -option is set for an unsupported architecture, a compile time error occurs. -See the -pcrejit -documentation for a discussion of JIT usage. When JIT support is enabled, -pcregrep automatically makes use of it, unless you add -
- --disable-pcregrep-jit --to the "configure" command. - -
-By default, PCRE interprets the linefeed (LF) character as indicating the end -of a line. This is the normal newline character on Unix-like systems. You can -compile PCRE to use carriage return (CR) instead, by adding -
- --enable-newline-is-cr --to the configure command. There is also a --enable-newline-is-lf option, -which explicitly specifies linefeed as the newline character. -
- --enable-newline-is-crlf --to the configure command. There is a fourth option, specified by -
- --enable-newline-is-anycrlf --which causes PCRE to recognize any of the three sequences CR, LF, or CRLF as -indicating a line ending. Finally, a fifth option, specified by -
- --enable-newline-is-any --causes PCRE to recognize any Unicode newline sequence. - -
-Whatever line ending convention is selected when PCRE is built can be -overridden when the library functions are called. At build time it is -conventional to use the standard for your operating system. -
--By default, the sequence \R in a pattern matches any Unicode newline sequence, -whatever has been selected as the line ending sequence. If you specify -
- --enable-bsr-anycrlf --the default is changed so that \R matches only CR, LF, or CRLF. Whatever is -selected when PCRE is built can be overridden when the library functions are -called. - -
-When the 8-bit library is called through the POSIX interface (see the -pcreposix -documentation), additional working storage is required for holding the pointers -to capturing substrings, because PCRE requires three integers per substring, -whereas the POSIX interface provides only two. If the number of expected -substrings is small, the wrapper function uses space on the stack, because this -is faster than using malloc() for each call. The default threshold above -which the stack is no longer used is 10; it can be changed by adding a setting -such as -
- --with-posix-malloc-threshold=20 --to the configure command. - -
-Within a compiled pattern, offset values are used to point from one part to -another (for example, from an opening parenthesis to an alternation -metacharacter). By default, in the 8-bit and 16-bit libraries, two-byte values -are used for these offsets, leading to a maximum size for a compiled pattern of -around 64K. This is sufficient to handle all but the most gigantic patterns. -Nevertheless, some people do want to process truly enormous patterns, so it is -possible to compile PCRE to use three-byte or four-byte offsets by adding a -setting such as -
- --with-link-size=3 --to the configure command. The value given must be 2, 3, or 4. For the -16-bit library, a value of 3 is rounded up to 4. In these libraries, using -longer offsets slows down the operation of PCRE because it has to load -additional data when handling them. For the 32-bit library the value is always -4 and cannot be overridden; the value of --with-link-size is ignored. - -
-When matching with the pcre_exec() function, PCRE implements backtracking -by making recursive calls to an internal function called match(). In -environments where the size of the stack is limited, this can severely limit -PCRE's operation. (The Unix environment does not usually suffer from this -problem, but it may sometimes be necessary to increase the maximum stack size. -There is a discussion in the -pcrestack -documentation.) An alternative approach to recursion that uses memory from the -heap to remember data, instead of using recursive function calls, has been -implemented to work round the problem of limited stack size. If you want to -build a version of PCRE that works this way, add -
- --disable-stack-for-recursion --to the configure command. With this configuration, PCRE will use the -pcre_stack_malloc and pcre_stack_free variables to call memory -management functions. By default these point to malloc() and -free(), but you can replace the pointers so that your own functions are -used instead. - -
-Separate functions are provided rather than using pcre_malloc and -pcre_free because the usage is very predictable: the block sizes -requested are always the same, and the blocks are always freed in reverse -order. A calling program might be able to implement optimized functions that -perform better than malloc() and free(). PCRE runs noticeably more -slowly when built in this way. This option affects only the pcre_exec() -function; it is not relevant for pcre_dfa_exec(). -
--Internally, PCRE has a function called match(), which it calls repeatedly -(sometimes recursively) when matching a pattern with the pcre_exec() -function. By controlling the maximum number of times this function may be -called during a single matching operation, a limit can be placed on the -resources used by a single call to pcre_exec(). The limit can be changed -at run time, as described in the -pcreapi -documentation. The default is 10 million, but this can be changed by adding a -setting such as -
- --with-match-limit=500000 --to the configure command. This setting has no effect on the -pcre_dfa_exec() matching function. - -
-In some environments it is desirable to limit the depth of recursive calls of -match() more strictly than the total number of calls, in order to -restrict the maximum amount of stack (or heap, if --disable-stack-for-recursion -is specified) that is used. A second limit controls this; it defaults to the -value that is set for --with-match-limit, which imposes no additional -constraints. However, you can set a lower limit by adding, for example, -
- --with-match-limit-recursion=10000 --to the configure command. This value can also be overridden at run time. - -
-PCRE uses fixed tables for processing characters whose code values are less -than 256. By default, PCRE is built with a set of tables that are distributed -in the file pcre_chartables.c.dist. These tables are for ASCII codes -only. If you add -
- --enable-rebuild-chartables --to the configure command, the distributed tables are no longer used. -Instead, a program called dftables is compiled and run. This outputs the -source for new set of tables, created in the default locale of your C run-time -system. (This method of replacing the tables does not work if you are cross -compiling, because dftables is run on the local host. If you need to -create alternative tables when cross compiling, you will have to do so "by -hand".) - -
-PCRE assumes by default that it will run in an environment where the character -code is ASCII (or Unicode, which is a superset of ASCII). This is the case for -most computer operating systems. PCRE can, however, be compiled to run in an -EBCDIC environment by adding -
- --enable-ebcdic --to the configure command. This setting implies ---enable-rebuild-chartables. You should only use it if you know that you are in -an EBCDIC environment (for example, an IBM mainframe operating system). The ---enable-ebcdic option is incompatible with --enable-utf. - -
-The EBCDIC character that corresponds to an ASCII LF is assumed to have the -value 0x15 by default. However, in some EBCDIC environments, 0x25 is used. In -such an environment you should use -
- --enable-ebcdic-nl25 --as well as, or instead of, --enable-ebcdic. The EBCDIC character for CR has the -same value as in ASCII, namely, 0x0d. Whichever of 0x15 and 0x25 is not -chosen as LF is made to correspond to the Unicode NEL character (which, in -Unicode, is 0x85). - -
-The options that select newline behaviour, such as --enable-newline-is-cr, -and equivalent run-time options, refer to these character values in an EBCDIC -environment. -
--By default, pcregrep reads all files as plain text. You can build it so -that it recognizes files whose names end in .gz or .bz2, and reads -them with libz or libbz2, respectively, by adding one or both of -
- --enable-pcregrep-libz - --enable-pcregrep-libbz2 --to the configure command. These options naturally require that the -relevant libraries are installed on your system. Configuration will fail if -they are not. - -
-pcregrep uses an internal buffer to hold a "window" on the file it is -scanning, in order to be able to output "before" and "after" lines when it -finds a match. The size of the buffer is controlled by a parameter whose -default value is 20K. The buffer itself is three times this size, but because -of the way it is used for holding "before" lines, the longest line that is -guaranteed to be processable is the parameter size. You can change the default -parameter value by adding, for example, -
- --with-pcregrep-bufsize=50K --to the configure command. The caller of \fPpcregrep\fP can, however, -override this value by specifying a run-time option. - -
-If you add -
- --enable-pcretest-libreadline --to the configure command, pcretest is linked with the -libreadline library, and when its input is from a terminal, it reads it -using the readline() function. This provides line-editing and history -facilities. Note that libreadline is GPL-licensed, so if you distribute a -binary of pcretest linked in this way, there may be licensing issues. - -
-Setting this option causes the -lreadline option to be added to the -pcretest build. In many operating environments with a sytem-installed -libreadline this is sufficient. However, in some environments (e.g. -if an unmodified distribution version of readline is in use), some extra -configuration may be necessary. The INSTALL file for libreadline says -this: -
- "Readline uses the termcap functions, but does not link with the - termcap or curses library itself, allowing applications which link - with readline the to choose an appropriate library." --If your environment has not been set up so that an appropriate library is -automatically included, you may need to add something like -
- LIBS="-ncurses" --immediately before the configure command. - -
-By adding the -
- --enable-valgrind --option to to the configure command, PCRE will use valgrind annotations -to mark certain memory regions as unaddressable. This allows it to detect -invalid memory accesses, and is mostly useful for debugging PCRE itself. - -
-If your C compiler is gcc, you can build a version of PCRE that can generate a -code coverage report for its test suite. To enable this, you must install -lcov version 1.6 or above. Then specify -
- --enable-coverage --to the configure command and build PCRE in the usual way. - -
-Note that using ccache (a caching C compiler) is incompatible with code -coverage reporting. If you have configured ccache to run automatically -on your system, you must set the environment variable -
- CCACHE_DISABLE=1 --before running make to build PCRE, so that ccache is not used. - -
-When --enable-coverage is used, the following addition targets are added to the -Makefile: -
- make coverage --This creates a fresh coverage report for the PCRE test suite. It is equivalent -to running "make coverage-reset", "make coverage-baseline", "make check", and -then "make coverage-report". -
- make coverage-reset --This zeroes the coverage counters, but does nothing else. -
- make coverage-baseline --This captures baseline coverage information. -
- make coverage-report --This creates the coverage report. -
- make coverage-clean-report --This removes the generated coverage report without cleaning the coverage data -itself. -
- make coverage-clean-data --This removes the captured coverage data without removing the coverage files -created at compile time (*.gcno). -
- make coverage-clean --This cleans all coverage data including the generated coverage report. For more -information about code coverage, see the gcov and lcov -documentation. - -
-pcreapi(3), pcre16, pcre32, pcre_config(3). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 May 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrecallout.html b/libs/Pcre16/docs/doc/html/pcrecallout.html deleted file mode 100644 index 53a937f52d..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrecallout.html +++ /dev/null @@ -1,286 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcre.h> -
--int (*pcre_callout)(pcre_callout_block *); -
--int (*pcre16_callout)(pcre16_callout_block *); -
--int (*pcre32_callout)(pcre32_callout_block *); -
--PCRE provides a feature called "callout", which is a means of temporarily -passing control to the caller of PCRE in the middle of pattern matching. The -caller of PCRE provides an external function by putting its entry point in the -global variable pcre_callout (pcre16_callout for the 16-bit -library, pcre32_callout for the 32-bit library). By default, this -variable contains NULL, which disables all calling out. -
--Within a regular expression, (?C) indicates the points at which the external -function is to be called. Different callout points can be identified by putting -a number less than 256 after the letter C. The default value is zero. -For example, this pattern has two callout points: -
- (?C1)abc(?C2)def --If the PCRE_AUTO_CALLOUT option bit is set when a pattern is compiled, PCRE -automatically inserts callouts, all with number 255, before each item in the -pattern. For example, if PCRE_AUTO_CALLOUT is used with the pattern -
- A(\d{2}|--) --it is processed as if it were -
- (?(?C9)(?=a)ab|de) --This applies only to assertion conditions (because they are themselves -independent groups). - -
-Automatic callouts can be used for tracking the progress of pattern matching. -The -pcretest -program has a pattern qualifier (/C) that sets automatic callouts; when it is -used, the output indicates how the pattern is being matched. This is useful -information when you are trying to optimize the performance of a particular -pattern. -
--You should be aware that, because of optimizations in the way PCRE compiles and -matches patterns, callouts sometimes do not happen exactly as you might expect. -
--At compile time, PCRE "auto-possessifies" repeated items when it knows that -what follows cannot be part of the repeat. For example, a+[bc] is compiled as -if it were a++[bc]. The pcretest output when this pattern is anchored and -then applied with automatic callouts to the string "aaaa" is: -
- --->aaaa - +0 ^ ^ - +1 ^ a+ - +3 ^ ^ [bc] - No match --This indicates that when matching [bc] fails, there is no backtracking into a+ -and therefore the callouts that would be taken for the backtracks do not occur. -You can disable the auto-possessify feature by passing PCRE_NO_AUTO_POSSESS -to pcre_compile(), or starting the pattern with (*NO_AUTO_POSSESS). If -this is done in pcretest (using the /O qualifier), the output changes to -this: -
- --->aaaa - +0 ^ ^ - +1 ^ a+ - +3 ^ ^ [bc] - +3 ^ ^ [bc] - +3 ^ ^ [bc] - +3 ^^ [bc] - No match --This time, when matching [bc] fails, the matcher backtracks into a+ and tries -again, repeatedly, until a+ itself fails. - -
-Other optimizations that provide fast "no match" results also affect callouts. -For example, if the pattern is -
- ab(?C4)cd --PCRE knows that any matching string must contain the letter "d". If the subject -string is "abyz", the lack of "d" means that matching doesn't ever start, and -the callout is never reached. However, with "abyd", though the result is still -no match, the callout is obeyed. - -
-If the pattern is studied, PCRE knows the minimum length of a matching string, -and will immediately give a "no match" return without actually running a match -if the subject is not long enough, or, for unanchored patterns, if it has -been scanned far enough. -
--You can disable these optimizations by passing the PCRE_NO_START_OPTIMIZE -option to the matching function, or by starting the pattern with -(*NO_START_OPT). This slows down the matching process, but does ensure that -callouts such as the example above are obeyed. -
--During matching, when PCRE reaches a callout point, the external function -defined by pcre_callout or pcre[16|32]_callout is called (if it is -set). This applies to both normal and DFA matching. The only argument to the -callout function is a pointer to a pcre_callout or -pcre[16|32]_callout block. These structures contains the following -fields: -
- int version; - int callout_number; - int *offset_vector; - const char *subject; (8-bit version) - PCRE_SPTR16 subject; (16-bit version) - PCRE_SPTR32 subject; (32-bit version) - int subject_length; - int start_match; - int current_position; - int capture_top; - int capture_last; - void *callout_data; - int pattern_position; - int next_item_length; - const unsigned char *mark; (8-bit version) - const PCRE_UCHAR16 *mark; (16-bit version) - const PCRE_UCHAR32 *mark; (32-bit version) --The version field is an integer containing the version number of the -block format. The initial version was 0; the current version is 2. The version -number will change again in future if additional fields are added, but the -intention is never to remove any of the existing fields. - -
-The callout_number field contains the number of the callout, as compiled -into the pattern (that is, the number after ?C for manual callouts, and 255 for -automatically generated callouts). -
--The offset_vector field is a pointer to the vector of offsets that was -passed by the caller to the matching function. When pcre_exec() or -pcre[16|32]_exec() is used, the contents can be inspected, in order to -extract substrings that have been matched so far, in the same way as for -extracting substrings after a match has completed. For the DFA matching -functions, this field is not useful. -
--The subject and subject_length fields contain copies of the values -that were passed to the matching function. -
--The start_match field normally contains the offset within the subject at -which the current match attempt started. However, if the escape sequence \K -has been encountered, this value is changed to reflect the modified starting -point. If the pattern is not anchored, the callout function may be called -several times from the same point in the pattern for different starting points -in the subject. -
--The current_position field contains the offset within the subject of the -current match pointer. -
--When the pcre_exec() or pcre[16|32]_exec() is used, the -capture_top field contains one more than the number of the highest -numbered captured substring so far. If no substrings have been captured, the -value of capture_top is one. This is always the case when the DFA -functions are used, because they do not support captured substrings. -
--The capture_last field contains the number of the most recently captured -substring. However, when a recursion exits, the value reverts to what it was -outside the recursion, as do the values of all captured substrings. If no -substrings have been captured, the value of capture_last is -1. This is -always the case for the DFA matching functions. -
--The callout_data field contains a value that is passed to a matching -function specifically so that it can be passed back in callouts. It is passed -in the callout_data field of a pcre_extra or pcre[16|32]_extra -data structure. If no such data was passed, the value of callout_data in -a callout block is NULL. There is a description of the pcre_extra -structure in the -pcreapi -documentation. -
--The pattern_position field is present from version 1 of the callout -structure. It contains the offset to the next item to be matched in the pattern -string. -
--The next_item_length field is present from version 1 of the callout -structure. It contains the length of the next item to be matched in the pattern -string. When the callout immediately precedes an alternation bar, a closing -parenthesis, or the end of the pattern, the length is zero. When the callout -precedes an opening parenthesis, the length is that of the entire subpattern. -
--The pattern_position and next_item_length fields are intended to -help in distinguishing between different automatic callouts, which all have the -same callout number. However, they are set for all callouts. -
--The mark field is present from version 2 of the callout structure. In -callouts from pcre_exec() or pcre[16|32]_exec() it contains a -pointer to the zero-terminated name of the most recently passed (*MARK), -(*PRUNE), or (*THEN) item in the match, or NULL if no such items have been -passed. Instances of (*PRUNE) or (*THEN) without a name do not obliterate a -previous (*MARK). In callouts from the DFA matching functions this field always -contains NULL. -
--The external callout function returns an integer to PCRE. If the value is zero, -matching proceeds as normal. If the value is greater than zero, matching fails -at the current point, but the testing of other matching possibilities goes -ahead, just as if a lookahead assertion had failed. If the value is less than -zero, the match is abandoned, the matching function returns the negative value. -
--Negative values should normally be chosen from the set of PCRE_ERROR_xxx -values. In particular, PCRE_ERROR_NOMATCH forces a standard "no match" failure. -The error number PCRE_ERROR_CALLOUT is reserved for use by callout functions; -it will never be used by PCRE itself. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 November 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrecompat.html b/libs/Pcre16/docs/doc/html/pcrecompat.html deleted file mode 100644 index d95570ef17..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrecompat.html +++ /dev/null @@ -1,235 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-DIFFERENCES BETWEEN PCRE AND PERL
-
-
-This document describes the differences in the ways that PCRE and Perl handle -regular expressions. The differences described here are with respect to Perl -versions 5.10 and above. -
--1. PCRE has only a subset of Perl's Unicode support. Details of what it does -have are given in the -pcreunicode -page. -
--2. PCRE allows repeat quantifiers only on parenthesized assertions, but they do -not mean what you might think. For example, (?!a){3} does not assert that the -next three characters are not "a". It just asserts that the next character is -not "a" three times (in principle: PCRE optimizes this to run the assertion -just once). Perl allows repeat quantifiers on other assertions such as \b, but -these do not seem to have any use. -
--3. Capturing subpatterns that occur inside negative lookahead assertions are -counted, but their entries in the offsets vector are never set. Perl sometimes -(but not always) sets its numerical variables from inside negative assertions. -
--4. Though binary zero characters are supported in the subject string, they are -not allowed in a pattern string because it is passed as a normal C string, -terminated by zero. The escape sequence \0 can be used in the pattern to -represent a binary zero. -
--5. The following Perl escape sequences are not supported: \l, \u, \L, -\U, and \N when followed by a character name or Unicode value. (\N on its -own, matching a non-newline character, is supported.) In fact these are -implemented by Perl's general string-handling and are not part of its pattern -matching engine. If any of these are encountered by PCRE, an error is -generated by default. However, if the PCRE_JAVASCRIPT_COMPAT option is set, -\U and \u are interpreted as JavaScript interprets them. -
--6. The Perl escape sequences \p, \P, and \X are supported only if PCRE is -built with Unicode character property support. The properties that can be -tested with \p and \P are limited to the general category properties such as -Lu and Nd, script names such as Greek or Han, and the derived properties Any -and L&. PCRE does support the Cs (surrogate) property, which Perl does not; the -Perl documentation says "Because Perl hides the need for the user to understand -the internal representation of Unicode characters, there is no need to -implement the somewhat messy concept of surrogates." -
--7. PCRE does support the \Q...\E escape for quoting substrings. Characters in -between are treated as literals. This is slightly different from Perl in that $ -and @ are also handled as literals inside the quotes. In Perl, they cause -variable interpolation (but of course PCRE does not have variables). Note the -following examples: -
- Pattern PCRE matches Perl matches - - \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz - \Qabc\$xyz\E abc\$xyz abc\$xyz - \Qabc\E\$\Qxyz\E abc$xyz abc$xyz --The \Q...\E sequence is recognized both inside and outside character classes. - -
-8. Fairly obviously, PCRE does not support the (?{code}) and (??{code}) -constructions. However, there is support for recursive patterns. This is not -available in Perl 5.8, but it is in Perl 5.10. Also, the PCRE "callout" -feature allows an external function to be called during pattern matching. See -the -pcrecallout -documentation for details. -
--9. Subpatterns that are called as subroutines (whether or not recursively) are -always treated as atomic groups in PCRE. This is like Python, but unlike Perl. -Captured values that are set outside a subroutine call can be reference from -inside in PCRE, but not in Perl. There is a discussion that explains these -differences in more detail in the -section on recursion differences from Perl -in the -pcrepattern -page. -
--10. If any of the backtracking control verbs are used in a subpattern that is -called as a subroutine (whether or not recursively), their effect is confined -to that subpattern; it does not extend to the surrounding pattern. This is not -always the case in Perl. In particular, if (*THEN) is present in a group that -is called as a subroutine, its action is limited to that group, even if the -group does not contain any | characters. Note that such subpatterns are -processed as anchored at the point where they are tested. -
--11. If a pattern contains more than one backtracking control verb, the first -one that is backtracked onto acts. For example, in the pattern -A(*COMMIT)B(*PRUNE)C a failure in B triggers (*COMMIT), but a failure in C -triggers (*PRUNE). Perl's behaviour is more complex; in many cases it is the -same as PCRE, but there are examples where it differs. -
--12. Most backtracking verbs in assertions have their normal actions. They are -not confined to the assertion. -
--13. There are some differences that are concerned with the settings of captured -strings when part of a pattern is repeated. For example, matching "aba" against -the pattern /^(a(b)?)+$/ in Perl leaves $2 unset, but in PCRE it is set to "b". -
--14. PCRE's handling of duplicate subpattern numbers and duplicate subpattern -names is not as general as Perl's. This is a consequence of the fact the PCRE -works internally just with numbers, using an external table to translate -between numbers and names. In particular, a pattern such as (?|(?<a>A)|(?<b>B), -where the two capturing parentheses have the same number but different names, -is not supported, and causes an error at compile time. If it were allowed, it -would not be possible to distinguish which parentheses matched, because both -names map to capturing subpattern number 1. To avoid this confusing situation, -an error is given at compile time. -
--15. Perl recognizes comments in some places that PCRE does not, for example, -between the ( and ? at the start of a subpattern. If the /x modifier is set, -Perl allows white space between ( and ? (though current Perls warn that this is -deprecated) but PCRE never does, even if the PCRE_EXTENDED option is set. -
--16. Perl, when in warning mode, gives warnings for character classes such as -[A-\d] or [a-[:digit:]]. It then treats the hyphens as literals. PCRE has no -warning features, so it gives an error in these cases because they are almost -certainly user mistakes. -
--17. In PCRE, the upper/lower case character properties Lu and Ll are not -affected when case-independent matching is specified. For example, \p{Lu} -always matches an upper case letter. I think Perl has changed in this respect; -in the release at the time of writing (5.16), \p{Lu} and \p{Ll} match all -letters, regardless of case, when case independence is specified. -
-
-18. PCRE provides some extensions to the Perl regular expression facilities.
-Perl 5.10 includes new features that are not in earlier versions of Perl, some
-of which (such as named parentheses) have been in PCRE for some time. This list
-is with respect to Perl 5.10:
-
-
-(a) Although lookbehind assertions in PCRE must match fixed length strings,
-each alternative branch of a lookbehind assertion can match a different length
-of string. Perl requires them all to have the same length.
-
-
-(b) If PCRE_DOLLAR_ENDONLY is set and PCRE_MULTILINE is not set, the $
-meta-character matches only at the very end of the string.
-
-
-(c) If PCRE_EXTRA is set, a backslash followed by a letter with no special
-meaning is faulted. Otherwise, like Perl, the backslash is quietly ignored.
-(Perl can be made to issue a warning.)
-
-
-(d) If PCRE_UNGREEDY is set, the greediness of the repetition quantifiers is
-inverted, that is, by default they are not greedy, but if followed by a
-question mark they are.
-
-
-(e) PCRE_ANCHORED can be used at matching time to force a pattern to be tried
-only at the first matching position in the subject string.
-
-
-(f) The PCRE_NOTBOL, PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, and
-PCRE_NO_AUTO_CAPTURE options for pcre_exec() have no Perl equivalents.
-
-
-(g) The \R escape sequence can be restricted to match only CR, LF, or CRLF
-by the PCRE_BSR_ANYCRLF option.
-
-
-(h) The callout facility is PCRE-specific.
-
-
-(i) The partial matching facility is PCRE-specific.
-
-
-(j) Patterns compiled by PCRE can be saved and re-used at a later time, even on
-different hosts that have the other endianness. However, this does not apply to
-optimized data created by the just-in-time compiler.
-
-
-(k) The alternative matching functions (pcre_dfa_exec(),
-pcre16_dfa_exec() and pcre32_dfa_exec(),) match in a different way
-and are not Perl-compatible.
-
-
-(l) PCRE recognizes some special sequences such as (*CR) at the start of
-a pattern that set overall options that cannot be changed within the pattern.
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 10 November 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrecpp.html b/libs/Pcre16/docs/doc/html/pcrecpp.html deleted file mode 100644 index b7eac3a3d7..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrecpp.html +++ /dev/null @@ -1,368 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcrecpp.h> -
--The C++ wrapper for PCRE was provided by Google Inc. Some additional -functionality was added by Giuseppe Maxia. This brief man page was constructed -from the notes in the pcrecpp.h file, which should be consulted for -further details. Note that the C++ wrapper supports only the original 8-bit -PCRE library. There is no 16-bit or 32-bit support at present. -
--The "FullMatch" operation checks that supplied text matches a supplied pattern -exactly. If pointer arguments are supplied, it copies matched sub-strings that -match sub-patterns into them. -
- Example: successful match - pcrecpp::RE re("h.*o"); - re.FullMatch("hello"); - - Example: unsuccessful match (requires full match): - pcrecpp::RE re("e"); - !re.FullMatch("hello"); - - Example: creating a temporary RE object: - pcrecpp::RE("h.*o").FullMatch("hello"); --You can pass in a "const char*" or a "string" for "text". The examples below -tend to use a const char*. You can, as in the different examples above, store -the RE object explicitly in a variable or use a temporary RE object. The -examples below use one mode or the other arbitrarily. Either could correctly be -used for any of these examples. - -
-You must supply extra pointer arguments to extract matched subpieces. -
- Example: extracts "ruby" into "s" and 1234 into "i" - int i; - string s; - pcrecpp::RE re("(\\w+):(\\d+)"); - re.FullMatch("ruby:1234", &s, &i); - - Example: does not try to extract any extra sub-patterns - re.FullMatch("ruby:1234", &s); - - Example: does not try to extract into NULL - re.FullMatch("ruby:1234", NULL, &i); - - Example: integer overflow causes failure - !re.FullMatch("ruby:1234567891234", NULL, &i); - - Example: fails because there aren't enough sub-patterns: - !pcrecpp::RE("\\w+:\\d+").FullMatch("ruby:1234", &s); - - Example: fails because string cannot be stored in integer - !pcrecpp::RE("(.*)").FullMatch("ruby", &i); --The provided pointer arguments can be pointers to any scalar numeric -type, or one of: -
- string (matched piece is copied to string) - StringPiece (StringPiece is mutated to point to matched piece) - T (where "bool T::ParseFrom(const char*, int)" exists) - NULL (the corresponding matched sub-pattern is not copied) --The function returns true iff all of the following conditions are satisfied: -
- a. "text" matches "pattern" exactly; - - b. The number of matched sub-patterns is >= number of supplied - pointers; - - c. The "i"th argument has a suitable type for holding the - string captured as the "i"th sub-pattern. If you pass in - void * NULL for the "i"th argument, or a non-void * NULL - of the correct type, or pass fewer arguments than the - number of sub-patterns, "i"th captured sub-pattern is - ignored. --CAVEAT: An optional sub-pattern that does not exist in the matched -string is assigned the empty string. Therefore, the following will -return false (because the empty string is not a valid number): -
- int number; - pcrecpp::RE::FullMatch("abc", "[a-z]+(\\d+)?", &number); --The matching interface supports at most 16 arguments per call. -If you need more, consider using the more general interface -pcrecpp::RE::DoMatch. See pcrecpp.h for the signature for -DoMatch. - -
-NOTE: Do not use no_arg, which is used internally to mark the end of a -list of optional arguments, as a placeholder for missing arguments, as this can -lead to segfaults. -
--You can use the "QuoteMeta" operation to insert backslashes before all -potentially meaningful characters in a string. The returned string, used as a -regular expression, will exactly match the original string. -
- Example: - string quoted = RE::QuoteMeta(unquoted); --Note that it's legal to escape a character even if it has no special meaning in -a regular expression -- so this function does that. (This also makes it -identical to the perl function of the same name; see "perldoc -f quotemeta".) -For example, "1.5-2.0?" becomes "1\.5\-2\.0\?". - -
-You can use the "PartialMatch" operation when you want the pattern -to match any substring of the text. -
- Example: simple search for a string: - pcrecpp::RE("ell").PartialMatch("hello"); - - Example: find first number in a string: - int number; - pcrecpp::RE re("(\\d+)"); - re.PartialMatch("x*100 + 20", &number); - assert(number == 100); -- -
-By default, pattern and text are plain text, one byte per character. The UTF8 -flag, passed to the constructor, causes both pattern and string to be treated -as UTF-8 text, still a byte stream but potentially multiple bytes per -character. In practice, the text is likelier to be UTF-8 than the pattern, but -the match returned may depend on the UTF8 flag, so always use it when matching -UTF8 text. For example, "." will match one byte normally but with UTF8 set may -match up to three bytes of a multi-byte character. -
- Example: - pcrecpp::RE_Options options; - options.set_utf8(); - pcrecpp::RE re(utf8_pattern, options); - re.FullMatch(utf8_string); - - Example: using the convenience function UTF8(): - pcrecpp::RE re(utf8_pattern, pcrecpp::UTF8()); - re.FullMatch(utf8_string); --NOTE: The UTF8 flag is ignored if pcre was not configured with the -
- --enable-utf8 flag. -- -
-PCRE defines some modifiers to change the behavior of the regular expression -engine. The C++ wrapper defines an auxiliary class, RE_Options, as a vehicle to -pass such modifiers to a RE class. Currently, the following modifiers are -supported: -
- modifier description Perl corresponding - - PCRE_CASELESS case insensitive match /i - PCRE_MULTILINE multiple lines match /m - PCRE_DOTALL dot matches newlines /s - PCRE_DOLLAR_ENDONLY $ matches only at end N/A - PCRE_EXTRA strict escape parsing N/A - PCRE_EXTENDED ignore white spaces /x - PCRE_UTF8 handles UTF8 chars built-in - PCRE_UNGREEDY reverses * and *? N/A - PCRE_NO_AUTO_CAPTURE disables capturing parens N/A (*) --(*) Both Perl and PCRE allow non capturing parentheses by means of the -"?:" modifier within the pattern itself. e.g. (?:ab|cd) does not -capture, while (ab|cd) does. - -
-For a full account on how each modifier works, please check the -PCRE API reference page. -
--For each modifier, there are two member functions whose name is made -out of the modifier in lowercase, without the "PCRE_" prefix. For -instance, PCRE_CASELESS is handled by -
- bool caseless() --which returns true if the modifier is set, and -
- RE_Options & set_caseless(bool) --which sets or unsets the modifier. Moreover, PCRE_EXTRA_MATCH_LIMIT can be -accessed through the set_match_limit() and match_limit() member -functions. Setting match_limit to a non-zero value will limit the -execution of pcre to keep it from doing bad things like blowing the stack or -taking an eternity to return a result. A value of 5000 is good enough to stop -stack blowup in a 2MB thread stack. Setting match_limit to zero disables -match limiting. Alternatively, you can call match_limit_recursion() -which uses PCRE_EXTRA_MATCH_LIMIT_RECURSION to limit how much PCRE -recurses. match_limit() limits the number of matches PCRE does; -match_limit_recursion() limits the depth of internal recursion, and -therefore the amount of stack that is used. - -
-Normally, to pass one or more modifiers to a RE class, you declare -a RE_Options object, set the appropriate options, and pass this -object to a RE constructor. Example: -
- RE_Options opt; - opt.set_caseless(true); - if (RE("HELLO", opt).PartialMatch("hello world")) ... --RE_options has two constructors. The default constructor takes no arguments and -creates a set of flags that are off by default. The optional parameter -option_flags is to facilitate transfer of legacy code from C programs. -This lets you do -
- RE(pattern, - RE_Options(PCRE_CASELESS|PCRE_MULTILINE)).PartialMatch(str); --However, new code is better off doing -
- RE(pattern, - RE_Options().set_caseless(true).set_multiline(true)) - .PartialMatch(str); --If you are going to pass one of the most used modifiers, there are some -convenience functions that return a RE_Options class with the -appropriate modifier already set: CASELESS(), UTF8(), -MULTILINE(), DOTALL(), and EXTENDED(). - -
-If you need to set several options at once, and you don't want to go through -the pains of declaring a RE_Options object and setting several options, there -is a parallel method that give you such ability on the fly. You can concatenate -several set_xxxxx() member functions, since each of them returns a -reference to its class object. For example, to pass PCRE_CASELESS, -PCRE_EXTENDED, and PCRE_MULTILINE to a RE with one statement, you may write: -
- RE(" ^ xyz \\s+ .* blah$", - RE_Options() - .set_caseless(true) - .set_extended(true) - .set_multiline(true)).PartialMatch(sometext); - -- -
-The "Consume" operation may be useful if you want to repeatedly -match regular expressions at the front of a string and skip over -them as they match. This requires use of the "StringPiece" type, -which represents a sub-range of a real string. Like RE, StringPiece -is defined in the pcrecpp namespace. -
- Example: read lines of the form "var = value" from a string. - string contents = ...; // Fill string somehow - pcrecpp::StringPiece input(contents); // Wrap in a StringPiece - - string var; - int value; - pcrecpp::RE re("(\\w+) = (\\d+)\n"); - while (re.Consume(&input, &var, &value)) { - ...; - } --Each successful call to "Consume" will set "var/value", and also -advance "input" so it points past the matched text. - -
-The "FindAndConsume" operation is similar to "Consume" but does not -anchor your match at the beginning of the string. For example, you -could extract all words from a string by repeatedly calling -
- pcrecpp::RE("(\\w+)").FindAndConsume(&input, &word) -- -
-By default, if you pass a pointer to a numeric value, the -corresponding text is interpreted as a base-10 number. You can -instead wrap the pointer with a call to one of the operators Hex(), -Octal(), or CRadix() to interpret the text in another base. The -CRadix operator interprets C-style "0" (base-8) and "0x" (base-16) -prefixes, but defaults to base-10. -
- Example: - int a, b, c, d; - pcrecpp::RE re("(.*) (.*) (.*) (.*)"); - re.FullMatch("100 40 0100 0x40", - pcrecpp::Octal(&a), pcrecpp::Hex(&b), - pcrecpp::CRadix(&c), pcrecpp::CRadix(&d)); --will leave 64 in a, b, c, and d. - -
-You can replace the first match of "pattern" in "str" with "rewrite". -Within "rewrite", backslash-escaped digits (\1 to \9) can be -used to insert text matching corresponding parenthesized group -from the pattern. \0 in "rewrite" refers to the entire matching -text. For example: -
- string s = "yabba dabba doo"; - pcrecpp::RE("b+").Replace("d", &s); --will leave "s" containing "yada dabba doo". The result is true if the pattern -matches and a replacement occurs, false otherwise. - -
-GlobalReplace is like Replace except that it replaces all -occurrences of the pattern in the string with the rewrite. Replacements are -not subject to re-matching. For example: -
- string s = "yabba dabba doo"; - pcrecpp::RE("b+").GlobalReplace("d", &s); --will leave "s" containing "yada dada doo". It returns the number of -replacements made. - -
-Extract is like Replace, except that if the pattern matches, -"rewrite" is copied into "out" (an additional argument) with substitutions. -The non-matching portions of "text" are ignored. Returns true iff a match -occurred and the extraction happened successfully; if no match occurs, the -string is left unaffected. -
-
-The C++ wrapper was contributed by Google Inc.
-
-Copyright © 2007 Google Inc.
-
-
-Last updated: 08 January 2012
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcredemo.html b/libs/Pcre16/docs/doc/html/pcredemo.html deleted file mode 100644 index 894a930826..0000000000 --- a/libs/Pcre16/docs/doc/html/pcredemo.html +++ /dev/null @@ -1,426 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-/************************************************* -* PCRE DEMONSTRATION PROGRAM * -*************************************************/ - -/* This is a demonstration program to illustrate the most straightforward ways -of calling the PCRE regular expression library from a C program. See the -pcresample documentation for a short discussion ("man pcresample" if you have -the PCRE man pages installed). - -In Unix-like environments, if PCRE is installed in your standard system -libraries, you should be able to compile this program using this command: - -gcc -Wall pcredemo.c -lpcre -o pcredemo - -If PCRE is not installed in a standard place, it is likely to be installed with -support for the pkg-config mechanism. If you have pkg-config, you can compile -this program using this command: - -gcc -Wall pcredemo.c `pkg-config --cflags --libs libpcre` -o pcredemo - -If you do not have pkg-config, you may have to use this: - -gcc -Wall pcredemo.c -I/usr/local/include -L/usr/local/lib \ - -R/usr/local/lib -lpcre -o pcredemo - -Replace "/usr/local/include" and "/usr/local/lib" with wherever the include and -library files for PCRE are installed on your system. Only some operating -systems (e.g. Solaris) use the -R option. - -Building under Windows: - -If you want to statically link this program against a non-dll .a file, you must -define PCRE_STATIC before including pcre.h, otherwise the pcre_malloc() and -pcre_free() exported functions will be declared __declspec(dllimport), with -unwanted results. So in this environment, uncomment the following line. */ - -/* #define PCRE_STATIC */ - -#include <stdio.h> -#include <string.h> -#include <pcre.h> - -#define OVECCOUNT 30 /* should be a multiple of 3 */ - - -int main(int argc, char **argv) -{ -pcre *re; -const char *error; -char *pattern; -char *subject; -unsigned char *name_table; -unsigned int option_bits; -int erroffset; -int find_all; -int crlf_is_newline; -int namecount; -int name_entry_size; -int ovector[OVECCOUNT]; -int subject_length; -int rc, i; -int utf8; - - -/************************************************************************** -* First, sort out the command line. There is only one possible option at * -* the moment, "-g" to request repeated matching to find all occurrences, * -* like Perl's /g option. We set the variable find_all to a non-zero value * -* if the -g option is present. Apart from that, there must be exactly two * -* arguments. * -**************************************************************************/ - -find_all = 0; -for (i = 1; i < argc; i++) - { - if (strcmp(argv[i], "-g") == 0) find_all = 1; - else break; - } - -/* After the options, we require exactly two arguments, which are the pattern, -and the subject string. */ - -if (argc - i != 2) - { - printf("Two arguments required: a regex and a subject string\n"); - return 1; - } - -pattern = argv[i]; -subject = argv[i+1]; -subject_length = (int)strlen(subject); - - -/************************************************************************* -* Now we are going to compile the regular expression pattern, and handle * -* and errors that are detected. * -*************************************************************************/ - -re = pcre_compile( - pattern, /* the pattern */ - 0, /* default options */ - &error, /* for error message */ - &erroffset, /* for error offset */ - NULL); /* use default character tables */ - -/* Compilation failed: print the error message and exit */ - -if (re == NULL) - { - printf("PCRE compilation failed at offset %d: %s\n", erroffset, error); - return 1; - } - - -/************************************************************************* -* If the compilation succeeded, we call PCRE again, in order to do a * -* pattern match against the subject string. This does just ONE match. If * -* further matching is needed, it will be done below. * -*************************************************************************/ - -rc = pcre_exec( - re, /* the compiled pattern */ - NULL, /* no extra data - we didn't study the pattern */ - subject, /* the subject string */ - subject_length, /* the length of the subject */ - 0, /* start at offset 0 in the subject */ - 0, /* default options */ - ovector, /* output vector for substring information */ - OVECCOUNT); /* number of elements in the output vector */ - -/* Matching failed: handle error cases */ - -if (rc < 0) - { - switch(rc) - { - case PCRE_ERROR_NOMATCH: printf("No match\n"); break; - /* - Handle other special cases if you like - */ - default: printf("Matching error %d\n", rc); break; - } - pcre_free(re); /* Release memory used for the compiled pattern */ - return 1; - } - -/* Match succeded */ - -printf("\nMatch succeeded at offset %d\n", ovector[0]); - - -/************************************************************************* -* We have found the first match within the subject string. If the output * -* vector wasn't big enough, say so. Then output any substrings that were * -* captured. * -*************************************************************************/ - -/* The output vector wasn't big enough */ - -if (rc == 0) - { - rc = OVECCOUNT/3; - printf("ovector only has room for %d captured substrings\n", rc - 1); - } - -/* Show substrings stored in the output vector by number. Obviously, in a real -application you might want to do things other than print them. */ - -for (i = 0; i < rc; i++) - { - char *substring_start = subject + ovector[2*i]; - int substring_length = ovector[2*i+1] - ovector[2*i]; - printf("%2d: %.*s\n", i, substring_length, substring_start); - } - - -/************************************************************************** -* That concludes the basic part of this demonstration program. We have * -* compiled a pattern, and performed a single match. The code that follows * -* shows first how to access named substrings, and then how to code for * -* repeated matches on the same subject. * -**************************************************************************/ - -/* See if there are any named substrings, and if so, show them by name. First -we have to extract the count of named parentheses from the pattern. */ - -(void)pcre_fullinfo( - re, /* the compiled pattern */ - NULL, /* no extra data - we didn't study the pattern */ - PCRE_INFO_NAMECOUNT, /* number of named substrings */ - &namecount); /* where to put the answer */ - -if (namecount <= 0) printf("No named substrings\n"); else - { - unsigned char *tabptr; - printf("Named substrings\n"); - - /* Before we can access the substrings, we must extract the table for - translating names to numbers, and the size of each entry in the table. */ - - (void)pcre_fullinfo( - re, /* the compiled pattern */ - NULL, /* no extra data - we didn't study the pattern */ - PCRE_INFO_NAMETABLE, /* address of the table */ - &name_table); /* where to put the answer */ - - (void)pcre_fullinfo( - re, /* the compiled pattern */ - NULL, /* no extra data - we didn't study the pattern */ - PCRE_INFO_NAMEENTRYSIZE, /* size of each entry in the table */ - &name_entry_size); /* where to put the answer */ - - /* Now we can scan the table and, for each entry, print the number, the name, - and the substring itself. */ - - tabptr = name_table; - for (i = 0; i < namecount; i++) - { - int n = (tabptr[0] << 8) | tabptr[1]; - printf("(%d) %*s: %.*s\n", n, name_entry_size - 3, tabptr + 2, - ovector[2*n+1] - ovector[2*n], subject + ovector[2*n]); - tabptr += name_entry_size; - } - } - - -/************************************************************************* -* If the "-g" option was given on the command line, we want to continue * -* to search for additional matches in the subject string, in a similar * -* way to the /g option in Perl. This turns out to be trickier than you * -* might think because of the possibility of matching an empty string. * -* What happens is as follows: * -* * -* If the previous match was NOT for an empty string, we can just start * -* the next match at the end of the previous one. * -* * -* If the previous match WAS for an empty string, we can't do that, as it * -* would lead to an infinite loop. Instead, a special call of pcre_exec() * -* is made with the PCRE_NOTEMPTY_ATSTART and PCRE_ANCHORED flags set. * -* The first of these tells PCRE that an empty string at the start of the * -* subject is not a valid match; other possibilities must be tried. The * -* second flag restricts PCRE to one match attempt at the initial string * -* position. If this match succeeds, an alternative to the empty string * -* match has been found, and we can print it and proceed round the loop, * -* advancing by the length of whatever was found. If this match does not * -* succeed, we still stay in the loop, advancing by just one character. * -* In UTF-8 mode, which can be set by (*UTF8) in the pattern, this may be * -* more than one byte. * -* * -* However, there is a complication concerned with newlines. When the * -* newline convention is such that CRLF is a valid newline, we must * -* advance by two characters rather than one. The newline convention can * -* be set in the regex by (*CR), etc.; if not, we must find the default. * -*************************************************************************/ - -if (!find_all) /* Check for -g */ - { - pcre_free(re); /* Release the memory used for the compiled pattern */ - return 0; /* Finish unless -g was given */ - } - -/* Before running the loop, check for UTF-8 and whether CRLF is a valid newline -sequence. First, find the options with which the regex was compiled; extract -the UTF-8 state, and mask off all but the newline options. */ - -(void)pcre_fullinfo(re, NULL, PCRE_INFO_OPTIONS, &option_bits); -utf8 = option_bits & PCRE_UTF8; -option_bits &= PCRE_NEWLINE_CR|PCRE_NEWLINE_LF|PCRE_NEWLINE_CRLF| - PCRE_NEWLINE_ANY|PCRE_NEWLINE_ANYCRLF; - -/* If no newline options were set, find the default newline convention from the -build configuration. */ - -if (option_bits == 0) - { - int d; - (void)pcre_config(PCRE_CONFIG_NEWLINE, &d); - /* Note that these values are always the ASCII ones, even in - EBCDIC environments. CR = 13, NL = 10. */ - option_bits = (d == 13)? PCRE_NEWLINE_CR : - (d == 10)? PCRE_NEWLINE_LF : - (d == (13<<8 | 10))? PCRE_NEWLINE_CRLF : - (d == -2)? PCRE_NEWLINE_ANYCRLF : - (d == -1)? PCRE_NEWLINE_ANY : 0; - } - -/* See if CRLF is a valid newline sequence. */ - -crlf_is_newline = - option_bits == PCRE_NEWLINE_ANY || - option_bits == PCRE_NEWLINE_CRLF || - option_bits == PCRE_NEWLINE_ANYCRLF; - -/* Loop for second and subsequent matches */ - -for (;;) - { - int options = 0; /* Normally no options */ - int start_offset = ovector[1]; /* Start at end of previous match */ - - /* If the previous match was for an empty string, we are finished if we are - at the end of the subject. Otherwise, arrange to run another match at the - same point to see if a non-empty match can be found. */ - - if (ovector[0] == ovector[1]) - { - if (ovector[0] == subject_length) break; - options = PCRE_NOTEMPTY_ATSTART | PCRE_ANCHORED; - } - - /* Run the next matching operation */ - - rc = pcre_exec( - re, /* the compiled pattern */ - NULL, /* no extra data - we didn't study the pattern */ - subject, /* the subject string */ - subject_length, /* the length of the subject */ - start_offset, /* starting offset in the subject */ - options, /* options */ - ovector, /* output vector for substring information */ - OVECCOUNT); /* number of elements in the output vector */ - - /* This time, a result of NOMATCH isn't an error. If the value in "options" - is zero, it just means we have found all possible matches, so the loop ends. - Otherwise, it means we have failed to find a non-empty-string match at a - point where there was a previous empty-string match. In this case, we do what - Perl does: advance the matching position by one character, and continue. We - do this by setting the "end of previous match" offset, because that is picked - up at the top of the loop as the point at which to start again. - - There are two complications: (a) When CRLF is a valid newline sequence, and - the current position is just before it, advance by an extra byte. (b) - Otherwise we must ensure that we skip an entire UTF-8 character if we are in - UTF-8 mode. */ - - if (rc == PCRE_ERROR_NOMATCH) - { - if (options == 0) break; /* All matches found */ - ovector[1] = start_offset + 1; /* Advance one byte */ - if (crlf_is_newline && /* If CRLF is newline & */ - start_offset < subject_length - 1 && /* we are at CRLF, */ - subject[start_offset] == '\r' && - subject[start_offset + 1] == '\n') - ovector[1] += 1; /* Advance by one more. */ - else if (utf8) /* Otherwise, ensure we */ - { /* advance a whole UTF-8 */ - while (ovector[1] < subject_length) /* character. */ - { - if ((subject[ovector[1]] & 0xc0) != 0x80) break; - ovector[1] += 1; - } - } - continue; /* Go round the loop again */ - } - - /* Other matching errors are not recoverable. */ - - if (rc < 0) - { - printf("Matching error %d\n", rc); - pcre_free(re); /* Release memory used for the compiled pattern */ - return 1; - } - - /* Match succeded */ - - printf("\nMatch succeeded again at offset %d\n", ovector[0]); - - /* The match succeeded, but the output vector wasn't big enough. */ - - if (rc == 0) - { - rc = OVECCOUNT/3; - printf("ovector only has room for %d captured substrings\n", rc - 1); - } - - /* As before, show substrings stored in the output vector by number, and then - also any named substrings. */ - - for (i = 0; i < rc; i++) - { - char *substring_start = subject + ovector[2*i]; - int substring_length = ovector[2*i+1] - ovector[2*i]; - printf("%2d: %.*s\n", i, substring_length, substring_start); - } - - if (namecount <= 0) printf("No named substrings\n"); else - { - unsigned char *tabptr = name_table; - printf("Named substrings\n"); - for (i = 0; i < namecount; i++) - { - int n = (tabptr[0] << 8) | tabptr[1]; - printf("(%d) %*s: %.*s\n", n, name_entry_size - 3, tabptr + 2, - ovector[2*n+1] - ovector[2*n], subject + ovector[2*n]); - tabptr += name_entry_size; - } - } - } /* End of loop to find second and subsequent matches */ - -printf("\n"); -pcre_free(re); /* Release memory used for the compiled pattern */ -return 0; -} - -/* End of pcredemo.c */ --Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcregrep.html b/libs/Pcre16/docs/doc/html/pcregrep.html deleted file mode 100644 index dacbb4998f..0000000000 --- a/libs/Pcre16/docs/doc/html/pcregrep.html +++ /dev/null @@ -1,759 +0,0 @@ - - -pcregrep specification - - -pcregrep man page
--Return to the PCRE index page. -
--This page is part of the PCRE HTML documentation. It was generated automatically -from the original man page. If there is any nonsense in it, please consult the -man page, in case the conversion went wrong. -
-
-pcregrep [options] [long options] [pattern] [path1 path2 ...] -
--pcregrep searches files for character patterns, in the same way as other -grep commands do, but it uses the PCRE regular expression library to support -patterns that are compatible with the regular expressions of Perl 5. See -pcresyntax(3) -for a quick-reference summary of pattern syntax, or -pcrepattern(3) -for a full description of the syntax and semantics of the regular expressions -that PCRE supports. -
--Patterns, whether supplied on the command line or in a separate file, are given -without delimiters. For example: -
- pcregrep Thursday /etc/motd --If you attempt to use delimiters (for example, by surrounding a pattern with -slashes, as is common in Perl scripts), they are interpreted as part of the -pattern. Quotes can of course be used to delimit patterns on the command line -because they are interpreted by the shell, and indeed quotes are required if a -pattern contains white space or shell metacharacters. - -
-The first argument that follows any option settings is treated as the single -pattern to be matched when neither -e nor -f is present. -Conversely, when one or both of these options are used to specify patterns, all -arguments are treated as path names. At least one of -e, -f, or an -argument pattern must be provided. -
--If no files are specified, pcregrep reads the standard input. The -standard input can also be referenced by a name consisting of a single hyphen. -For example: -
- pcregrep some-pattern /file1 - /file3 --By default, each line that matches a pattern is copied to the standard -output, and if there is more than one file, the file name is output at the -start of each line, followed by a colon. However, there are options that can -change how pcregrep behaves. In particular, the -M option makes it -possible to search for patterns that span line boundaries. What defines a line -boundary is controlled by the -N (--newline) option. - -
-The amount of memory used for buffering files that are being scanned is -controlled by a parameter that can be set by the --buffer-size option. -The default value for this parameter is specified when pcregrep is built, -with the default default being 20K. A block of memory three times this size is -used (to allow for buffering "before" and "after" lines). An error occurs if a -line overflows the buffer. -
--Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. -BUFSIZ is defined in <stdio.h>. When there is more than one pattern -(specified by the use of -e and/or -f), each pattern is applied to -each line in the order in which they are defined, except that all the -e -patterns are tried before the -f patterns. -
--By default, as soon as one pattern matches a line, no further patterns are -considered. However, if --colour (or --color) is used to colour the -matching substrings, or if --only-matching, --file-offsets, or ---line-offsets is used to output only the part of the line that matched -(either shown literally, or as an offset), scanning resumes immediately -following the match, so that further matches on the same line can be found. If -there are multiple patterns, they are all tried on the remainder of the line, -but patterns that follow the one that matched are not tried on the earlier part -of the line. -
--This behaviour means that the order in which multiple patterns are specified -can affect the output when one of the above options is used. This is no longer -the same behaviour as GNU grep, which now manages to display earlier matches -for later patterns (as long as there is no overlap). -
--Patterns that can match an empty string are accepted, but empty string -matches are never recognized. An example is the pattern "(super)?(man)?", in -which all components are optional. This pattern finds all occurrences of both -"super" and "man"; the output differs from matching with "super|man" when only -the matching substrings are being shown. -
--If the LC_ALL or LC_CTYPE environment variable is set, -pcregrep uses the value to set a locale when calling the PCRE library. -The --locale option can be used to override this. -
--It is possible to compile pcregrep so that it uses libz or -libbz2 to read files whose names end in .gz or .bz2, -respectively. You can find out whether your binary has support for one or both -of these file types by running it with the --help option. If the -appropriate support is not present, files are treated as plain text. The -standard input is always so treated. -
--By default, a file that contains a binary zero byte within the first 1024 bytes -is identified as a binary file, and is processed specially. (GNU grep also -identifies binary files in this manner.) See the --binary-files option -for a means of changing the way binary files are handled. -
--The order in which some of the options appear can affect the output. For -example, both the -h and -l options affect the printing of file -names. Whichever comes later in the command line will be the one that takes -effect. Similarly, except where noted below, if an option is given twice, the -later setting is used. Numerical values for options may be followed by K or M, -to signify multiplication by 1024 or 1024*1024 respectively. -
---- -This terminates the list of options. It is useful if the next item on the -command line starts with a hyphen but is not an option. This allows for the -processing of patterns and filenames that start with hyphens. -
---A number, --after-context=number -Output number lines of context after each matching line. If filenames -and/or line numbers are being output, a hyphen separator is used instead of a -colon for the context lines. A line containing "--" is output between each -group of lines, unless they are in fact contiguous in the input file. The value -of number is expected to be relatively small. However, pcregrep -guarantees to have up to 8K of following text available for context output. -
---a, --text -Treat binary files as text. This is equivalent to ---binary-files=text. -
---B number, --before-context=number -Output number lines of context before each matching line. If filenames -and/or line numbers are being output, a hyphen separator is used instead of a -colon for the context lines. A line containing "--" is output between each -group of lines, unless they are in fact contiguous in the input file. The value -of number is expected to be relatively small. However, pcregrep -guarantees to have up to 8K of preceding text available for context output. -
----binary-files=word -Specify how binary files are to be processed. If the word is "binary" (the -default), pattern matching is performed on binary files, but the only output is -"Binary file <name> matches" when a match succeeds. If the word is "text", -which is equivalent to the -a or --text option, binary files are -processed in the same way as any other file. In this case, when a match -succeeds, the output may be binary garbage, which can have nasty effects if -sent to a terminal. If the word is "without-match", which is equivalent to the --I option, binary files are not processed at all; they are assumed not to -be of interest. -
----buffer-size=number -Set the parameter that controls how much memory is used for buffering files -that are being scanned. -
---C number, --context=number -Output number lines of context both before and after each matching line. -This is equivalent to setting both -A and -B to the same value. -
---c, --count -Do not output individual lines from the files that are being scanned; instead -output the number of lines that would otherwise have been shown. If no lines -are selected, the number zero is output. If several files are are being -scanned, a count is output for each of them. However, if the ---files-with-matches option is also used, only those files whose counts -are greater than zero are listed. When -c is used, the -A, --B, and -C options are ignored. -
----colour, --color -If this option is given without any data, it is equivalent to "--colour=auto". -If data is required, it must be given in the same shell item, separated by an -equals sign. -
-
---colour=value, --color=value
-This option specifies under what circumstances the parts of a line that matched
-a pattern should be coloured in the output. By default, the output is not
-coloured. The value (which is optional, see above) may be "never", "always", or
-"auto". In the latter case, colouring happens only if the standard output is
-connected to a terminal. More resources are used when colouring is enabled,
-because pcregrep has to search for all possible matches in a line, not
-just one, in order to colour them all.
-
-
-The colour that is used can be specified by setting the environment variable
-PCREGREP_COLOUR or PCREGREP_COLOR. The value of this variable should be a
-string of two numbers, separated by a semicolon. They are copied directly into
-the control string for setting colour on a terminal, so it is your
-responsibility to ensure that they make sense. If neither of the environment
-variables is set, the default is "1;31", which gives red.
-
--D action, --devices=action -If an input path is not a regular file or a directory, "action" specifies how -it is to be processed. Valid values are "read" (the default) or "skip" -(silently skip the path). -
---d action, --directories=action -If an input path is a directory, "action" specifies how it is to be processed. -Valid values are "read" (the default in non-Windows environments, for -compatibility with GNU grep), "recurse" (equivalent to the -r option), or -"skip" (silently skip the path, the default in Windows environments). In the -"read" case, directories are read as if they were ordinary files. In some -operating systems the effect of reading a directory like this is an immediate -end-of-file; in others it may provoke an error. -
-
--e pattern, --regex=pattern, --regexp=pattern
-Specify a pattern to be matched. This option can be used multiple times in
-order to specify several patterns. It can also be used as a way of specifying a
-single pattern that starts with a hyphen. When -e is used, no argument
-pattern is taken from the command line; all arguments are treated as file
-names. There is no limit to the number of patterns. They are applied to each
-line in the order in which they are defined until one matches.
-
-
-If -f is used with -e, the command line patterns are matched first,
-followed by the patterns from the file(s), independent of the order in which
-these options are specified. Note that multiple use of -e is not the same
-as a single pattern with alternatives. For example, X|Y finds the first
-character in a line that is X or Y, whereas if the two patterns are given
-separately, with X first, pcregrep finds X if it is present, even if it
-follows Y in the line. It finds Y only if there is no X in the line. This
-matters only if you are using -o or --colo(u)r to show the part(s)
-of the line that matched.
-
---exclude=pattern -Files (but not directories) whose names match the pattern are skipped without -being processed. This applies to all files, whether listed on the command line, -obtained from --file-list, or by scanning a directory. The pattern is a -PCRE regular expression, and is matched against the final component of the file -name, not the entire path. The -F, -w, and -x options do not -apply to this pattern. The option may be given any number of times in order to -specify multiple patterns. If a file name matches both an --include -and an --exclude pattern, it is excluded. There is no short form for this -option. -
----exclude-from=filename -Treat each non-empty line of the file as the data for an --exclude -option. What constitutes a newline when reading the file is the operating -system's default. The --newline option has no effect on this option. This -option may be given more than once in order to specify a number of files to -read. -
----exclude-dir=pattern -Directories whose names match the pattern are skipped without being processed, -whatever the setting of the --recursive option. This applies to all -directories, whether listed on the command line, obtained from ---file-list, or by scanning a parent directory. The pattern is a PCRE -regular expression, and is matched against the final component of the directory -name, not the entire path. The -F, -w, and -x options do not -apply to this pattern. The option may be given any number of times in order to -specify more than one pattern. If a directory matches both --include-dir -and --exclude-dir, it is excluded. There is no short form for this -option. -
---F, --fixed-strings -Interpret each data-matching pattern as a list of fixed strings, separated by -newlines, instead of as a regular expression. What constitutes a newline for -this purpose is controlled by the --newline option. The -w (match -as a word) and -x (match whole line) options can be used with -F. -They apply to each of the fixed strings. A line is selected if any of the fixed -strings are found in it (subject to -w or -x, if present). This -option applies only to the patterns that are matched against the contents of -files; it does not apply to patterns specified by any of the --include or ---exclude options. -
-
--f filename, --file=filename
-Read patterns from the file, one per line, and match them against
-each line of input. What constitutes a newline when reading the file is the
-operating system's default. The --newline option has no effect on this
-option. Trailing white space is removed from each line, and blank lines are
-ignored. An empty file contains no patterns and therefore matches nothing. See
-also the comments about multiple patterns versus a single pattern with
-alternatives in the description of -e above.
-
-
-If this option is given more than once, all the specified files are
-read. A data line is output if any of the patterns match it. A filename can
-be given as "-" to refer to the standard input. When -f is used, patterns
-specified on the command line using -e may also be present; they are
-tested before the file's patterns. However, no other pattern is taken from the
-command line; all arguments are treated as the names of paths to be searched.
-
---file-list=filename -Read a list of files and/or directories that are to be scanned from the given -file, one per line. Trailing white space is removed from each line, and blank -lines are ignored. These paths are processed before any that are listed on the -command line. The filename can be given as "-" to refer to the standard input. -If --file and --file-list are both specified as "-", patterns are -read first. This is useful only when the standard input is a terminal, from -which further lines (the list of files) can be read after an end-of-file -indication. If this option is given more than once, all the specified files are -read. -
----file-offsets -Instead of showing lines or parts of lines that match, show each match as an -offset from the start of the file and a length, separated by a comma. In this -mode, no context is shown. That is, the -A, -B, and -C -options are ignored. If there is more than one match in a line, each of them is -shown separately. This option is mutually exclusive with --line-offsets -and --only-matching. -
---H, --with-filename -Force the inclusion of the filename at the start of output lines when searching -a single file. By default, the filename is not shown in this case. For matching -lines, the filename is followed by a colon; for context lines, a hyphen -separator is used. If a line number is also being output, it follows the file -name. -
---h, --no-filename -Suppress the output filenames when searching multiple files. By default, -filenames are shown when multiple files are searched. For matching lines, the -filename is followed by a colon; for context lines, a hyphen separator is used. -If a line number is also being output, it follows the file name. -
----help -Output a help message, giving brief details of the command options and file -type support, and then exit. Anything else on the command line is -ignored. -
---I -Treat binary files as never matching. This is equivalent to ---binary-files=without-match. -
---i, --ignore-case -Ignore upper/lower case distinctions during comparisons. -
----include=pattern -If any --include patterns are specified, the only files that are -processed are those that match one of the patterns (and do not match an ---exclude pattern). This option does not affect directories, but it -applies to all files, whether listed on the command line, obtained from ---file-list, or by scanning a directory. The pattern is a PCRE regular -expression, and is matched against the final component of the file name, not -the entire path. The -F, -w, and -x options do not apply to -this pattern. The option may be given any number of times. If a file name -matches both an --include and an --exclude pattern, it is excluded. -There is no short form for this option. -
----include-from=filename -Treat each non-empty line of the file as the data for an --include -option. What constitutes a newline for this purpose is the operating system's -default. The --newline option has no effect on this option. This option -may be given any number of times; all the files are read. -
----include-dir=pattern -If any --include-dir patterns are specified, the only directories that -are processed are those that match one of the patterns (and do not match an ---exclude-dir pattern). This applies to all directories, whether listed -on the command line, obtained from --file-list, or by scanning a parent -directory. The pattern is a PCRE regular expression, and is matched against the -final component of the directory name, not the entire path. The -F, --w, and -x options do not apply to this pattern. The option may be -given any number of times. If a directory matches both --include-dir and ---exclude-dir, it is excluded. There is no short form for this option. -
---L, --files-without-match -Instead of outputting lines from the files, just output the names of the files -that do not contain any lines that would have been output. Each file name is -output once, on a separate line. -
---l, --files-with-matches -Instead of outputting lines from the files, just output the names of the files -containing lines that would have been output. Each file name is output -once, on a separate line. Searching normally stops as soon as a matching line -is found in a file. However, if the -c (count) option is also used, -matching continues in order to obtain the correct count, and those files that -have at least one match are listed along with their counts. Using this option -with -c is a way of suppressing the listing of files with no matches. -
----label=name -This option supplies a name to be used for the standard input when file names -are being output. If not supplied, "(standard input)" is used. There is no -short form for this option. -
----line-buffered -When this option is given, input is read and processed line by line, and the -output is flushed after each write. By default, input is read in large chunks, -unless pcregrep can determine that it is reading from a terminal (which -is currently possible only in Unix-like environments). Output to terminal is -normally automatically flushed by the operating system. This option can be -useful when the input or output is attached to a pipe and you do not want -pcregrep to buffer up large amounts of data. However, its use will affect -performance, and the -M (multiline) option ceases to work. -
----line-offsets -Instead of showing lines or parts of lines that match, show each match as a -line number, the offset from the start of the line, and a length. The line -number is terminated by a colon (as usual; see the -n option), and the -offset and length are separated by a comma. In this mode, no context is shown. -That is, the -A, -B, and -C options are ignored. If there is -more than one match in a line, each of them is shown separately. This option is -mutually exclusive with --file-offsets and --only-matching. -
----locale=locale-name -This option specifies a locale to be used for pattern matching. It overrides -the value in the LC_ALL or LC_CTYPE environment variables. If no -locale is specified, the PCRE library's default (usually the "C" locale) is -used. There is no short form for this option. -
-
---match-limit=number
-Processing some regular expression patterns can require a very large amount of
-memory, leading in some cases to a program crash if not enough is available.
-Other patterns may take a very long time to search for all possible matching
-strings. The pcre_exec() function that is called by pcregrep to do
-the matching has two parameters that can limit the resources that it uses.
-
-
-The --match-limit option provides a means of limiting resource usage
-when processing patterns that are not going to match, but which have a very
-large number of possibilities in their search trees. The classic example is a
-pattern that uses nested unlimited repeats. Internally, PCRE uses a function
-called match() which it calls repeatedly (sometimes recursively). The
-limit set by --match-limit is imposed on the number of times this
-function is called during a match, which has the effect of limiting the amount
-of backtracking that can take place.
-
-
-The --recursion-limit option is similar to --match-limit, but
-instead of limiting the total number of times that match() is called, it
-limits the depth of recursive calls, which in turn limits the amount of memory
-that can be used. The recursion depth is a smaller number than the total number
-of calls, because not all calls to match() are recursive. This limit is
-of use only if it is set smaller than --match-limit.
-
-
-There are no short forms for these options. The default settings are specified
-when the PCRE library is compiled, with the default default being 10 million.
-
--M, --multiline
-Allow patterns to match more than one line. When this option is given, patterns
-may usefully contain literal newline characters and internal occurrences of ^
-and $ characters. The output for a successful match may consist of more than
-one line, the last of which is the one in which the match ended. If the matched
-string ends with a newline sequence the output ends at the end of that line.
-
-
-When this option is set, the PCRE library is called in "multiline" mode.
-There is a limit to the number of lines that can be matched, imposed by the way
-that pcregrep buffers the input file as it scans it. However,
-pcregrep ensures that at least 8K characters or the rest of the document
-(whichever is the shorter) are available for forward matching, and similarly
-the previous 8K characters (or all the previous characters, if fewer than 8K)
-are guaranteed to be available for lookbehind assertions. This option does not
-work when input is read line by line (see \fP--line-buffered\fP.)
-
--N newline-type, --newline=newline-type
-The PCRE library supports five different conventions for indicating
-the ends of lines. They are the single-character sequences CR (carriage return)
-and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention,
-which recognizes any of the preceding three types, and an "any" convention, in
-which any Unicode line ending sequence is assumed to end a line. The Unicode
-sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF
-(form feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and
-PS (paragraph separator, U+2029).
-
-
-When the PCRE library is built, a default line-ending sequence is specified.
-This is normally the standard sequence for the operating system. Unless
-otherwise specified by this option, pcregrep uses the library's default.
-The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
-makes it possible to use pcregrep to scan files that have come from other
-environments without having to modify their line endings. If the data that is
-being scanned does not agree with the convention set by this option,
-pcregrep may behave in strange ways. Note that this option does not
-apply to files specified by the -f, --exclude-from, or
---include-from options, which are expected to use the operating system's
-standard newline sequence.
-
--n, --line-number -Precede each output line by its line number in the file, followed by a colon -for matching lines or a hyphen for context lines. If the filename is also being -output, it precedes the line number. This option is forced if ---line-offsets is used. -
----no-jit -If the PCRE library is built with support for just-in-time compiling (which -speeds up matching), pcregrep automatically makes use of this, unless it -was explicitly disabled at build time. This option can be used to disable the -use of JIT at run time. It is provided for testing and working round problems. -It should never be needed in normal use. -
---o, --only-matching -Show only the part of the line that matched a pattern instead of the whole -line. In this mode, no context is shown. That is, the -A, -B, and --C options are ignored. If there is more than one match in a line, each -of them is shown separately. If -o is combined with -v (invert the -sense of the match to find non-matching lines), no output is generated, but the -return code is set appropriately. If the matched portion of the line is empty, -nothing is output unless the file name or line number are being printed, in -which case they are shown on an otherwise empty line. This option is mutually -exclusive with --file-offsets and --line-offsets. -
-
--onumber, --only-matching=number
-Show only the part of the line that matched the capturing parentheses of the
-given number. Up to 32 capturing parentheses are supported, and -o0 is
-equivalent to -o without a number. Because these options can be given
-without an argument (see above), if an argument is present, it must be given in
-the same shell item, for example, -o3 or --only-matching=2. The comments given
-for the non-argument case above also apply to this case. If the specified
-capturing parentheses do not exist in the pattern, or were not set in the
-match, nothing is output unless the file name or line number are being printed.
-
-
-If this option is given multiple times, multiple substrings are output, in the
-order the options are given. For example, -o3 -o1 -o3 causes the substrings
-matched by capturing parentheses 3 and 1 and then 3 again to be output. By
-default, there is no separator (but see the next option).
-
---om-separator=text -Specify a separating string for multiple occurrences of -o. The default -is an empty string. Separating strings are never coloured. -
---q, --quiet -Work quietly, that is, display nothing except error messages. The exit -status indicates whether or not any matches were found. -
---r, --recursive -If any given path is a directory, recursively scan the files it contains, -taking note of any --include and --exclude settings. By default, a -directory is read as a normal file; in some operating systems this gives an -immediate end-of-file. This option is a shorthand for setting the -d -option to "recurse". -
----recursion-limit=number -See --match-limit above. -
---s, --no-messages -Suppress error messages about non-existent or unreadable files. Such files are -quietly skipped. However, the return code is still 2, even if matches were -found in other files. -
---u, --utf-8 -Operate in UTF-8 mode. This option is available only if PCRE has been compiled -with UTF-8 support. All patterns (including those for any --exclude and ---include options) and all subject lines that are scanned must be valid -strings of UTF-8 characters. -
---V, --version -Write the version numbers of pcregrep and the PCRE library to the -standard output and then exit. Anything else on the command line is -ignored. -
---v, --invert-match -Invert the sense of the match, so that lines which do not match any of -the patterns are the ones that are found. -
---w, --word-regex, --word-regexp -Force the patterns to match only whole words. This is equivalent to having \b -at the start and end of the pattern. This option applies only to the patterns -that are matched against the contents of files; it does not apply to patterns -specified by any of the --include or --exclude options. -
---x, --line-regex, --line-regexp -Force the patterns to be anchored (each must start matching at the beginning of -a line) and in addition, require them to match entire lines. This is equivalent -to having ^ and $ characters at the start and end of each alternative branch in -every pattern. This option applies only to the patterns that are matched -against the contents of files; it does not apply to patterns specified by any -of the --include or --exclude options. -
--The environment variables LC_ALL and LC_CTYPE are examined, in that -order, for a locale. The first one that is set is used. This can be overridden -by the --locale option. If no locale is set, the PCRE library's default -(usually the "C" locale) is used. -
--The -N (--newline) option allows pcregrep to scan files with -different newline conventions from the default. Any parts of the input files -that are written to the standard output are copied identically, with whatever -newline sequences they have in the input. However, the setting of this option -does not affect the interpretation of files specified by the -f, ---exclude-from, or --include-from options, which are assumed to use -the operating system's standard newline sequence, nor does it affect the way in -which pcregrep writes informational messages to the standard error and -output streams. For these it uses the string "\n" to indicate newlines, -relying on the C I/O library to convert this to an appropriate sequence. -
--Many of the short and long forms of pcregrep's options are the same -as in the GNU grep program. Any long option of the form ---xxx-regexp (GNU terminology) is also available as --xxx-regex -(PCRE terminology). However, the --file-list, --file-offsets, ---include-dir, --line-offsets, --locale, --match-limit, --M, --multiline, -N, --newline, --om-separator, ---recursion-limit, -u, and --utf-8 options are specific to -pcregrep, as is the use of the --only-matching option with a -capturing parentheses number. -
--Although most of the common options work the same way, a few are different in -pcregrep. For example, the --include option's argument is a glob -for GNU grep, but a regular expression for pcregrep. If both the --c and -l options are given, GNU grep lists only file names, -without counts, but pcregrep gives the counts. -
--There are four different ways in which an option with data can be specified. -If a short form option is used, the data may follow immediately, or (with one -exception) in the next command line item. For example: -
- -f/some/file - -f /some/file --The exception is the -o option, which may appear with or without data. -Because of this, if data is present, it must follow immediately in the same -item, for example -o3. - -
-If a long form option is used, the data may appear in the same command line -item, separated by an equals character, or (with two exceptions) it may appear -in the next command line item. For example: -
- --file=/some/file - --file /some/file --Note, however, that if you want to supply a file name beginning with ~ as data -in a shell command, and have the shell expand ~ to a home directory, you must -separate the file name from the option, because the shell does not treat ~ -specially unless it is at the start of an item. - -
-The exceptions to the above are the --colour (or --color) and ---only-matching options, for which the data is optional. If one of these -options does have data, it must be given in the first form, using an equals -character. Otherwise pcregrep will assume that it has no data. -
--It is possible to supply a regular expression that takes a very long time to -fail to match certain lines. Such patterns normally involve nested indefinite -repeats, for example: (a+)*\d when matched against a line of a's with no final -digit. The PCRE matching function has a resource limit that causes it to abort -in these circumstances. If this happens, pcregrep outputs an error -message and the line that caused the problem to the standard error stream. If -there are more than 20 such errors, pcregrep gives up. -
--The --match-limit option of pcregrep can be used to set the overall -resource limit; there is a second option called --recursion-limit that -sets a limit on the amount of memory (usually stack) that is used (see the -discussion of these options above). -
--Exit status is 0 if any matches were found, 1 if no matches were found, and 2 -for syntax errors, overlong lines, non-existent or inaccessible files (even if -matches were found in other files) or too many matching errors. Using the --s option to suppress error messages about inaccessible files does not -affect the return code. -
--pcrepattern(3), pcresyntax(3), pcretest(1). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 03 April 2014
-
-Copyright © 1997-2014 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrejit.html b/libs/Pcre16/docs/doc/html/pcrejit.html deleted file mode 100644 index abb342522f..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrejit.html +++ /dev/null @@ -1,499 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-Just-in-time compiling is a heavyweight optimization that can greatly speed up -pattern matching. However, it comes at the cost of extra processing before the -match is performed. Therefore, it is of most benefit when the same pattern is -going to be matched many times. This does not necessarily mean many calls of a -matching function; if the pattern is not anchored, matching attempts may take -place many times at various positions in the subject, even for a single call. -Therefore, if the subject string is very long, it may still pay to use JIT for -one-off matches. -
--JIT support applies only to the traditional Perl-compatible matching function. -It does not apply when the DFA matching function is being used. The code for -this support was written by Zoltan Herczeg. -
--JIT support is available for all of the 8-bit, 16-bit and 32-bit PCRE -libraries. To keep this documentation simple, only the 8-bit interface is -described in what follows. If you are using the 16-bit library, substitute the -16-bit functions and 16-bit structures (for example, pcre16_jit_stack -instead of pcre_jit_stack). If you are using the 32-bit library, -substitute the 32-bit functions and 32-bit structures (for example, -pcre32_jit_stack instead of pcre_jit_stack). -
--JIT support is an optional feature of PCRE. The "configure" option --enable-jit -(or equivalent CMake option) must be set when PCRE is built if you want to use -JIT. The support is limited to the following hardware platforms: -
- ARM v5, v7, and Thumb2 - Intel x86 32-bit and 64-bit - MIPS 32-bit - Power PC 32-bit and 64-bit - SPARC 32-bit (experimental) --If --enable-jit is set on an unsupported platform, compilation fails. - -
-A program that is linked with PCRE 8.20 or later can tell if JIT support is -available by calling pcre_config() with the PCRE_CONFIG_JIT option. The -result is 1 when JIT is available, and 0 otherwise. However, a simple program -does not need to check this in order to use JIT. The normal API is implemented -in a way that falls back to the interpretive code if JIT is not available. For -programs that need the best possible performance, there is also a "fast path" -API that is JIT-specific. -
--If your program may sometimes be linked with versions of PCRE that are older -than 8.20, but you want to use JIT when it is available, you can test the -values of PCRE_MAJOR and PCRE_MINOR, or the existence of a JIT macro such as -PCRE_CONFIG_JIT, for compile-time control of your code. Also beware that the -pcre_jit_exec() function was not available at all before 8.32, -and may not be available at all if PCRE isn't compiled with ---enable-jit. See the "JIT FAST PATH API" section below for details. -
--You have to do two things to make use of the JIT support in the simplest way: -
- (1) Call pcre_study() with the PCRE_STUDY_JIT_COMPILE option for - each compiled pattern, and pass the resulting pcre_extra block to - pcre_exec(). - - (2) Use pcre_free_study() to free the pcre_extra block when it is - no longer needed, instead of just freeing it yourself. This ensures that - any JIT data is also freed. --For a program that may be linked with pre-8.20 versions of PCRE, you can insert -
- #ifndef PCRE_STUDY_JIT_COMPILE - #define PCRE_STUDY_JIT_COMPILE 0 - #endif --so that no option is passed to pcre_study(), and then use something like -this to free the study data: -
- #ifdef PCRE_CONFIG_JIT - pcre_free_study(study_ptr); - #else - pcre_free(study_ptr); - #endif --PCRE_STUDY_JIT_COMPILE requests the JIT compiler to generate code for complete -matches. If you want to run partial matches using the PCRE_PARTIAL_HARD or -PCRE_PARTIAL_SOFT options of pcre_exec(), you should set one or both of -the following options in addition to, or instead of, PCRE_STUDY_JIT_COMPILE -when you call pcre_study(): -
- PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE - PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE --If using pcre_jit_exec() and supporting a pre-8.32 version of -PCRE, you can insert: -
- #if PCRE_MAJOR >= 8 && PCRE_MINOR >= 32 - pcre_jit_exec(...); - #else - pcre_exec(...) - #endif --but as described in the "JIT FAST PATH API" section below this assumes -version 8.32 and later are compiled with --enable-jit, which may -break. -
-In some circumstances you may need to call additional functions. These are -described in the section entitled -"Controlling the JIT stack" -below. -
--If JIT support is not available, PCRE_STUDY_JIT_COMPILE etc. are ignored, and -no JIT data is created. Otherwise, the compiled pattern is passed to the JIT -compiler, which turns it into machine code that executes much faster than the -normal interpretive code. When pcre_exec() is passed a pcre_extra -block containing a pointer to JIT code of the appropriate mode (normal or -hard/soft partial), it obeys that code instead of running the interpreter. The -result is identical, but the compiled JIT code runs much faster. -
--There are some pcre_exec() options that are not supported for JIT -execution. There are also some pattern items that JIT cannot handle. Details -are given below. In both cases, execution automatically falls back to the -interpretive code. If you want to know whether JIT was actually used for a -particular match, you should arrange for a JIT callback function to be set up -as described in the section entitled -"Controlling the JIT stack" -below, even if you do not need to supply a non-default JIT stack. Such a -callback function is called whenever JIT code is about to be obeyed. If the -execution options are not right for JIT execution, the callback function is not -obeyed. -
--If the JIT compiler finds an unsupported item, no JIT data is generated. You -can find out if JIT execution is available after studying a pattern by calling -pcre_fullinfo() with the PCRE_INFO_JIT option. A result of 1 means that -JIT compilation was successful. A result of 0 means that JIT support is not -available, or the pattern was not studied with PCRE_STUDY_JIT_COMPILE etc., or -the JIT compiler was not able to handle the pattern. -
--Once a pattern has been studied, with or without JIT, it can be used as many -times as you like for matching different subject strings. -
--The only pcre_exec() options that are supported for JIT execution are -PCRE_NO_UTF8_CHECK, PCRE_NO_UTF16_CHECK, PCRE_NO_UTF32_CHECK, PCRE_NOTBOL, -PCRE_NOTEOL, PCRE_NOTEMPTY, PCRE_NOTEMPTY_ATSTART, PCRE_PARTIAL_HARD, and -PCRE_PARTIAL_SOFT. -
--The only unsupported pattern items are \C (match a single data unit) when -running in a UTF mode, and a callout immediately before an assertion condition -in a conditional group. -
--When a pattern is matched using JIT execution, the return values are the same -as those given by the interpretive pcre_exec() code, with the addition of -one new error code: PCRE_ERROR_JIT_STACKLIMIT. This means that the memory used -for the JIT stack was insufficient. See -"Controlling the JIT stack" -below for a discussion of JIT stack usage. For compatibility with the -interpretive pcre_exec() code, no more than two-thirds of the -ovector argument is used for passing back captured substrings. -
--The error code PCRE_ERROR_MATCHLIMIT is returned by the JIT code if searching a -very large pattern tree goes on for too long, as it is in the same circumstance -when JIT is not used, but the details of exactly what is counted are not the -same. The PCRE_ERROR_RECURSIONLIMIT error code is never returned by JIT -execution. -
--The code that is generated by the JIT compiler is architecture-specific, and is -also position dependent. For those reasons it cannot be saved (in a file or -database) and restored later like the bytecode and other data of a compiled -pattern. Saving and restoring compiled patterns is not something many people -do. More detail about this facility is given in the -pcreprecompile -documentation. It should be possible to run pcre_study() on a saved and -restored pattern, and thereby recreate the JIT data, but because JIT -compilation uses significant resources, it is probably not worth doing this; -you might as well recompile the original pattern. -
--When the compiled JIT code runs, it needs a block of memory to use as a stack. -By default, it uses 32K on the machine stack. However, some large or -complicated patterns need more than this. The error PCRE_ERROR_JIT_STACKLIMIT -is given when there is not enough stack. Three functions are provided for -managing blocks of memory for use as JIT stacks. There is further discussion -about the use of JIT stacks in the section entitled -"JIT stack FAQ" -below. -
--The pcre_jit_stack_alloc() function creates a JIT stack. Its arguments -are a starting size and a maximum size, and it returns a pointer to an opaque -structure of type pcre_jit_stack, or NULL if there is an error. The -pcre_jit_stack_free() function can be used to free a stack that is no -longer needed. (For the technically minded: the address space is allocated by -mmap or VirtualAlloc.) -
--JIT uses far less memory for recursion than the interpretive code, -and a maximum stack size of 512K to 1M should be more than enough for any -pattern. -
--The pcre_assign_jit_stack() function specifies which stack JIT code -should use. Its arguments are as follows: -
- pcre_extra *extra - pcre_jit_callback callback - void *data --The extra argument must be the result of studying a pattern with -PCRE_STUDY_JIT_COMPILE etc. There are three cases for the values of the other -two options: -
- (1) If callback is NULL and data is NULL, an internal 32K block - on the machine stack is used. - - (2) If callback is NULL and data is not NULL, data must be - a valid JIT stack, the result of calling pcre_jit_stack_alloc(). - - (3) If callback is not NULL, it must point to a function that is - called with data as an argument at the start of matching, in - order to set up a JIT stack. If the return from the callback - function is NULL, the internal 32K stack is used; otherwise the - return value must be a valid JIT stack, the result of calling - pcre_jit_stack_alloc(). --A callback function is obeyed whenever JIT code is about to be run; it is not -obeyed when pcre_exec() is called with options that are incompatible for -JIT execution. A callback function can therefore be used to determine whether a -match operation was executed by JIT or by the interpreter. - -
-You may safely use the same JIT stack for more than one pattern (either by -assigning directly or by callback), as long as the patterns are all matched -sequentially in the same thread. In a multithread application, if you do not -specify a JIT stack, or if you assign or pass back NULL from a callback, that -is thread-safe, because each thread has its own machine stack. However, if you -assign or pass back a non-NULL JIT stack, this must be a different stack for -each thread so that the application is thread-safe. -
--Strictly speaking, even more is allowed. You can assign the same non-NULL stack -to any number of patterns as long as they are not used for matching by multiple -threads at the same time. For example, you can assign the same stack to all -compiled patterns, and use a global mutex in the callback to wait until the -stack is available for use. However, this is an inefficient solution, and not -recommended. -
--This is a suggestion for how a multithreaded program that needs to set up -non-default JIT stacks might operate: -
- During thread initalization - thread_local_var = pcre_jit_stack_alloc(...) - - During thread exit - pcre_jit_stack_free(thread_local_var) - - Use a one-line callback function - return thread_local_var --All the functions described in this section do nothing if JIT is not available, -and pcre_assign_jit_stack() does nothing unless the extra argument -is non-NULL and points to a pcre_extra block that is the result of a -successful study with PCRE_STUDY_JIT_COMPILE etc. - -
-(1) Why do we need JIT stacks?
-
-
-PCRE (and JIT) is a recursive, depth-first engine, so it needs a stack where
-the local data of the current node is pushed before checking its child nodes.
-Allocating real machine stack on some platforms is difficult. For example, the
-stack chain needs to be updated every time if we extend the stack on PowerPC.
-Although it is possible, its updating time overhead decreases performance. So
-we do the recursion in memory.
-
-(2) Why don't we simply allocate blocks of memory with malloc()?
-
-
-Modern operating systems have a nice feature: they can reserve an address space
-instead of allocating memory. We can safely allocate memory pages inside this
-address space, so the stack could grow without moving memory data (this is
-important because of pointers). Thus we can allocate 1M address space, and use
-only a single memory page (usually 4K) if that is enough. However, we can still
-grow up to 1M anytime if needed.
-
-(3) Who "owns" a JIT stack?
-
-
-The owner of the stack is the user program, not the JIT studied pattern or
-anything else. The user program must ensure that if a stack is used by
-pcre_exec(), (that is, it is assigned to the pattern currently running),
-that stack must not be used by any other threads (to avoid overwriting the same
-memory area). The best practice for multithreaded programs is to allocate a
-stack for each thread, and return this stack through the JIT callback function.
-
-(4) When should a JIT stack be freed?
-
-
-You can free a JIT stack at any time, as long as it will not be used by
-pcre_exec() again. When you assign the stack to a pattern, only a pointer
-is set. There is no reference counting or any other magic. You can free the
-patterns and stacks in any order, anytime. Just do not call
-pcre_exec() with a pattern pointing to an already freed stack, as that
-will cause SEGFAULT. (Also, do not free a stack currently used by
-pcre_exec() in another thread). You can also replace the stack for a
-pattern at any time. You can even free the previous stack before assigning a
-replacement.
-
-(5) Should I allocate/free a stack every time before/after calling
-pcre_exec()?
-
-
-No, because this is too costly in terms of resources. However, you could
-implement some clever idea which release the stack if it is not used in let's
-say two minutes. The JIT callback can help to achieve this without keeping a
-list of the currently JIT studied patterns.
-
-(6) OK, the stack is for long term memory allocation. But what happens if a
-pattern causes stack overflow with a stack of 1M? Is that 1M kept until the
-stack is freed?
-
-
-Especially on embedded sytems, it might be a good idea to release memory
-sometimes without freeing the stack. There is no API for this at the moment.
-Probably a function call which returns with the currently allocated memory for
-any stack and another which allows releasing memory (shrinking the stack) would
-be a good idea if someone needs this.
-
-(7) This is too much of a headache. Isn't there any better solution for JIT
-stack handling?
-
-
-No, thanks to Windows. If POSIX threads were used everywhere, we could throw
-out this complicated API.
-
-This is a single-threaded example that specifies a JIT stack without using a -callback. -
- int rc; - int ovector[30]; - pcre *re; - pcre_extra *extra; - pcre_jit_stack *jit_stack; - - re = pcre_compile(pattern, 0, &error, &erroffset, NULL); - /* Check for errors */ - extra = pcre_study(re, PCRE_STUDY_JIT_COMPILE, &error); - jit_stack = pcre_jit_stack_alloc(32*1024, 512*1024); - /* Check for error (NULL) */ - pcre_assign_jit_stack(extra, NULL, jit_stack); - rc = pcre_exec(re, extra, subject, length, 0, 0, ovector, 30); - /* Check results */ - pcre_free(re); - pcre_free_study(extra); - pcre_jit_stack_free(jit_stack); - -- -
-Because the API described above falls back to interpreted execution when JIT is -not available, it is convenient for programs that are written for general use -in many environments. However, calling JIT via pcre_exec() does have a -performance impact. Programs that are written for use where JIT is known to be -available, and which need the best possible performance, can instead use a -"fast path" API to call JIT execution directly instead of calling -pcre_exec() (obviously only for patterns that have been successfully -studied by JIT). -
--The fast path function is called pcre_jit_exec(), and it takes exactly -the same arguments as pcre_exec(), plus one additional argument that -must point to a JIT stack. The JIT stack arrangements described above do not -apply. The return values are the same as for pcre_exec(). -
--When you call pcre_exec(), as well as testing for invalid options, a -number of other sanity checks are performed on the arguments. For example, if -the subject pointer is NULL, or its length is negative, an immediate error is -given. Also, unless PCRE_NO_UTF[8|16|32] is set, a UTF subject string is tested -for validity. In the interests of speed, these checks do not happen on the JIT -fast path, and if invalid data is passed, the result is undefined. -
--Bypassing the sanity checks and the pcre_exec() wrapping can give -speedups of more than 10%. -
--Note that the pcre_jit_exec() function is not available in versions of -PCRE before 8.32 (released in November 2012). If you need to support versions -that old you must either use the slower pcre_exec(), or switch between -the two codepaths by checking the values of PCRE_MAJOR and PCRE_MINOR. -
--Due to an unfortunate implementation oversight, even in versions 8.32 -and later there will be no pcre_jit_exec() stub function defined -when PCRE is compiled with --disable-jit, which is the default, and -there's no way to detect whether PCRE was compiled with --enable-jit -via a macro. -
--If you need to support versions older than 8.32, or versions that may -not build with --enable-jit, you must either use the slower -pcre_exec(), or switch between the two codepaths by checking the -values of PCRE_MAJOR and PCRE_MINOR. -
--Switching between the two by checking the version assumes that all the -versions being targeted are built with --enable-jit. To also support -builds that may use --disable-jit either pcre_exec() must be -used, or a compile-time check for JIT via pcre_config() (which -assumes the runtime environment will be the same), or as the Git -project decided to do, simply assume that pcre_jit_exec() is -present in 8.32 or later unless a compile-time flag is provided, see -the "grep: un-break building with PCRE >= 8.32 without --enable-jit" -commit in git.git for an example of that. -
--pcreapi(3) -
-
-Philip Hazel (FAQ by Zoltan Herczeg)
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 05 July 2017
-
-Copyright © 1997-2017 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrelimits.html b/libs/Pcre16/docs/doc/html/pcrelimits.html deleted file mode 100644 index ee5ebf033d..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrelimits.html +++ /dev/null @@ -1,90 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-SIZE AND OTHER LIMITATIONS
-
-
-There are some size limitations in PCRE but it is hoped that they will never in -practice be relevant. -
--The maximum length of a compiled pattern is approximately 64K data units (bytes -for the 8-bit library, 16-bit units for the 16-bit library, and 32-bit units for -the 32-bit library) if PCRE is compiled with the default internal linkage size, -which is 2 bytes for the 8-bit and 16-bit libraries, and 4 bytes for the 32-bit -library. If you want to process regular expressions that are truly enormous, -you can compile PCRE with an internal linkage size of 3 or 4 (when building the -16-bit or 32-bit library, 3 is rounded up to 4). See the README file in -the source distribution and the -pcrebuild -documentation for details. In these cases the limit is substantially larger. -However, the speed of execution is slower. -
--All values in repeating quantifiers must be less than 65536. -
--There is no limit to the number of parenthesized subpatterns, but there can be -no more than 65535 capturing subpatterns. There is, however, a limit to the -depth of nesting of parenthesized subpatterns of all kinds. This is imposed in -order to limit the amount of system stack used at compile time. The limit can -be specified when PCRE is built; the default is 250. -
--There is a limit to the number of forward references to subsequent subpatterns -of around 200,000. Repeated forward references with fixed upper limits, for -example, (?2){0,100} when subpattern number 2 is to the right, are included in -the count. There is no limit to the number of backward references. -
--The maximum length of name for a named subpattern is 32 characters, and the -maximum number of named subpatterns is 10000. -
--The maximum length of a name in a (*MARK), (*PRUNE), (*SKIP), or (*THEN) verb -is 255 for the 8-bit library and 65535 for the 16-bit and 32-bit libraries. -
--The maximum length of a subject string is the largest positive number that an -integer variable can hold. However, when using the traditional matching -function, PCRE uses recursion to handle subpatterns and indefinite repetition. -This means that the available stack space may limit the size of a subject -string that can be processed by certain patterns. For a discussion of stack -issues, see the -pcrestack -documentation. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 05 November 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrematching.html b/libs/Pcre16/docs/doc/html/pcrematching.html deleted file mode 100644 index a1af39b68d..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrematching.html +++ /dev/null @@ -1,242 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-This document describes the two different algorithms that are available in PCRE -for matching a compiled regular expression against a given subject string. The -"standard" algorithm is the one provided by the pcre_exec(), -pcre16_exec() and pcre32_exec() functions. These work in the same -as as Perl's matching function, and provide a Perl-compatible matching operation. -The just-in-time (JIT) optimization that is described in the -pcrejit -documentation is compatible with these functions. -
--An alternative algorithm is provided by the pcre_dfa_exec(), -pcre16_dfa_exec() and pcre32_dfa_exec() functions; they operate in -a different way, and are not Perl-compatible. This alternative has advantages -and disadvantages compared with the standard algorithm, and these are described -below. -
--When there is only one possible way in which a given subject string can match a -pattern, the two algorithms give the same answer. A difference arises, however, -when there are multiple possibilities. For example, if the pattern -
- ^<.*> --is matched against the string -
- <something> <something else> <something further> --there are three possible answers. The standard algorithm finds only one of -them, whereas the alternative algorithm finds all three. - -
-The set of strings that are matched by a regular expression can be represented -as a tree structure. An unlimited repetition in the pattern makes the tree of -infinite size, but it is still a tree. Matching the pattern to a given subject -string (from a given starting point) can be thought of as a search of the tree. -There are two ways to search a tree: depth-first and breadth-first, and these -correspond to the two matching algorithms provided by PCRE. -
--In the terminology of Jeffrey Friedl's book "Mastering Regular -Expressions", the standard algorithm is an "NFA algorithm". It conducts a -depth-first search of the pattern tree. That is, it proceeds along a single -path through the tree, checking that the subject matches what is required. When -there is a mismatch, the algorithm tries any alternatives at the current point, -and if they all fail, it backs up to the previous branch point in the tree, and -tries the next alternative branch at that level. This often involves backing up -(moving to the left) in the subject string as well. The order in which -repetition branches are tried is controlled by the greedy or ungreedy nature of -the quantifier. -
--If a leaf node is reached, a matching string has been found, and at that point -the algorithm stops. Thus, if there is more than one possible match, this -algorithm returns the first one that it finds. Whether this is the shortest, -the longest, or some intermediate length depends on the way the greedy and -ungreedy repetition quantifiers are specified in the pattern. -
--Because it ends up with a single path through the tree, it is relatively -straightforward for this algorithm to keep track of the substrings that are -matched by portions of the pattern in parentheses. This provides support for -capturing parentheses and back references. -
--This algorithm conducts a breadth-first search of the tree. Starting from the -first matching point in the subject, it scans the subject string from left to -right, once, character by character, and as it does this, it remembers all the -paths through the tree that represent valid matches. In Friedl's terminology, -this is a kind of "DFA algorithm", though it is not implemented as a -traditional finite state machine (it keeps multiple states active -simultaneously). -
--Although the general principle of this matching algorithm is that it scans the -subject string only once, without backtracking, there is one exception: when a -lookaround assertion is encountered, the characters following or preceding the -current point have to be independently inspected. -
--The scan continues until either the end of the subject is reached, or there are -no more unterminated paths. At this point, terminated paths represent the -different matching possibilities (if there are none, the match has failed). -Thus, if there is more than one possible match, this algorithm finds all of -them, and in particular, it finds the longest. The matches are returned in -decreasing order of length. There is an option to stop the algorithm after the -first match (which is necessarily the shortest) is found. -
--Note that all the matches that are found start at the same point in the -subject. If the pattern -
- cat(er(pillar)?)? --is matched against the string "the caterpillar catchment", the result will be -the three strings "caterpillar", "cater", and "cat" that start at the fifth -character of the subject. The algorithm does not automatically move on to find -matches that start at later positions. - -
-PCRE's "auto-possessification" optimization usually applies to character -repeats at the end of a pattern (as well as internally). For example, the -pattern "a\d+" is compiled as if it were "a\d++" because there is no point -even considering the possibility of backtracking into the repeated digits. For -DFA matching, this means that only one possible match is found. If you really -do want multiple matches in such cases, either use an ungreedy repeat -("a\d+?") or set the PCRE_NO_AUTO_POSSESS option when compiling. -
--There are a number of features of PCRE regular expressions that are not -supported by the alternative matching algorithm. They are as follows: -
--1. Because the algorithm finds all possible matches, the greedy or ungreedy -nature of repetition quantifiers is not relevant. Greedy and ungreedy -quantifiers are treated in exactly the same way. However, possessive -quantifiers can make a difference when what follows could also match what is -quantified, for example in a pattern like this: -
- ^a++\w! --This pattern matches "aaab!" but not "aaa!", which would be matched by a -non-possessive quantifier. Similarly, if an atomic group is present, it is -matched as if it were a standalone pattern at the current point, and the -longest match is then "locked in" for the rest of the overall pattern. - -
-2. When dealing with multiple paths through the tree simultaneously, it is not -straightforward to keep track of captured substrings for the different matching -possibilities, and PCRE's implementation of this algorithm does not attempt to -do this. This means that no captured substrings are available. -
--3. Because no substrings are captured, back references within the pattern are -not supported, and cause errors if encountered. -
--4. For the same reason, conditional expressions that use a backreference as the -condition or test for a specific group recursion are not supported. -
--5. Because many paths through the tree may be active, the \K escape sequence, -which resets the start of the match when encountered (but may be on some paths -and not on others), is not supported. It causes an error if encountered. -
--6. Callouts are supported, but the value of the capture_top field is -always 1, and the value of the capture_last field is always -1. -
--7. The \C escape sequence, which (in the standard algorithm) always matches a -single data unit, even in UTF-8, UTF-16 or UTF-32 modes, is not supported in -these modes, because the alternative algorithm moves through the subject string -one character (not data unit) at a time, for all active paths through the tree. -
--8. Except for (*FAIL), the backtracking control verbs such as (*PRUNE) are not -supported. (*FAIL) is supported, and behaves like a failing negative assertion. -
--Using the alternative matching algorithm provides the following advantages: -
--1. All possible matches (at a single point in the subject) are automatically -found, and in particular, the longest match is found. To find more than one -match using the standard algorithm, you have to do kludgy things with -callouts. -
--2. Because the alternative algorithm scans the subject string just once, and -never needs to backtrack (except for lookbehinds), it is possible to pass very -long subject strings to the matching function in several pieces, checking for -partial matching each time. Although it is possible to do multi-segment -matching using the standard algorithm by retaining partially matched -substrings, it is more complicated. The -pcrepartial -documentation gives details of partial matching and discusses multi-segment -matching. -
--The alternative algorithm suffers from a number of disadvantages: -
--1. It is substantially slower than the standard algorithm. This is partly -because it has to search for all possible matches, but is also because it is -less susceptible to optimization. -
--2. Capturing parentheses and back references are not supported. -
--3. Although atomic groups are supported, their use does not provide the -performance advantage that it does for the standard algorithm. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 November 2013
-
-Copyright © 1997-2012 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrepartial.html b/libs/Pcre16/docs/doc/html/pcrepartial.html deleted file mode 100644 index 4faeafcb68..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrepartial.html +++ /dev/null @@ -1,509 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-In normal use of PCRE, if the subject string that is passed to a matching -function matches as far as it goes, but is too short to match the entire -pattern, PCRE_ERROR_NOMATCH is returned. There are circumstances where it might -be helpful to distinguish this case from other cases in which there is no -match. -
--Consider, for example, an application where a human is required to type in data -for a field with specific formatting requirements. An example might be a date -in the form ddmmmyy, defined by this pattern: -
- ^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$ --If the application sees the user's keystrokes one by one, and can check that -what has been typed so far is potentially valid, it is able to raise an error -as soon as a mistake is made, by beeping and not reflecting the character that -has been typed, for example. This immediate feedback is likely to be a better -user interface than a check that is delayed until the entire string has been -entered. Partial matching can also be useful when the subject string is very -long and is not all available at once. - -
-PCRE supports partial matching by means of the PCRE_PARTIAL_SOFT and -PCRE_PARTIAL_HARD options, which can be set when calling any of the matching -functions. For backwards compatibility, PCRE_PARTIAL is a synonym for -PCRE_PARTIAL_SOFT. The essential difference between the two options is whether -or not a partial match is preferred to an alternative complete match, though -the details differ between the two types of matching function. If both options -are set, PCRE_PARTIAL_HARD takes precedence. -
--If you want to use partial matching with just-in-time optimized code, you must -call pcre_study(), pcre16_study() or pcre32_study() with one -or both of these options: -
- PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE - PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE --PCRE_STUDY_JIT_COMPILE should also be set if you are going to run non-partial -matches on the same pattern. If the appropriate JIT study mode has not been set -for a match, the interpretive matching code is used. - -
-Setting a partial matching option disables two of PCRE's standard -optimizations. PCRE remembers the last literal data unit in a pattern, and -abandons matching immediately if it is not present in the subject string. This -optimization cannot be used for a subject string that might match only -partially. If the pattern was studied, PCRE knows the minimum length of a -matching string, and does not bother to run the matching function on shorter -strings. This optimization is also disabled for partial matching. -
--A partial match occurs during a call to pcre_exec() or -pcre[16|32]_exec() when the end of the subject string is reached -successfully, but matching cannot continue because more characters are needed. -However, at least one character in the subject must have been inspected. This -character need not form part of the final matched string; lookbehind assertions -and the \K escape sequence provide ways of inspecting characters before the -start of a matched substring. The requirement for inspecting at least one -character exists because an empty string can always be matched; without such a -restriction there would always be a partial match of an empty string at the end -of the subject. -
--If there are at least two slots in the offsets vector when a partial match is -returned, the first slot is set to the offset of the earliest character that -was inspected. For convenience, the second offset points to the end of the -subject so that a substring can easily be identified. If there are at least -three slots in the offsets vector, the third slot is set to the offset of the -character where matching started. -
--For the majority of patterns, the contents of the first and third slots will be -the same. However, for patterns that contain lookbehind assertions, or begin -with \b or \B, characters before the one where matching started may have been -inspected while carrying out the match. For example, consider this pattern: -
- /(?<=abc)123/ --This pattern matches "123", but only if it is preceded by "abc". If the subject -string is "xyzabc12", the first two offsets after a partial match are for the -substring "abc12", because all these characters were inspected. However, the -third offset is set to 6, because that is the offset where matching began. - -
-What happens when a partial match is identified depends on which of the two -partial matching options are set. -
--If PCRE_PARTIAL_SOFT is set when pcre_exec() or pcre[16|32]_exec() -identifies a partial match, the partial match is remembered, but matching -continues as normal, and other alternatives in the pattern are tried. If no -complete match can be found, PCRE_ERROR_PARTIAL is returned instead of -PCRE_ERROR_NOMATCH. -
--This option is "soft" because it prefers a complete match over a partial match. -All the various matching items in a pattern behave as if the subject string is -potentially complete. For example, \z, \Z, and $ match at the end of the -subject, as normal, and for \b and \B the end of the subject is treated as a -non-alphanumeric. -
--If there is more than one partial match, the first one that was found provides -the data that is returned. Consider this pattern: -
- /123\w+X|dogY/ --If this is matched against the subject string "abc123dog", both -alternatives fail to match, but the end of the subject is reached during -matching, so PCRE_ERROR_PARTIAL is returned. The offsets are set to 3 and 9, -identifying "123dog" as the first partial match that was found. (In this -example, there are two partial matches, because "dog" on its own partially -matches the second alternative.) - -
-If PCRE_PARTIAL_HARD is set for pcre_exec() or pcre[16|32]_exec(), -PCRE_ERROR_PARTIAL is returned as soon as a partial match is found, without -continuing to search for possible complete matches. This option is "hard" -because it prefers an earlier partial match over a later complete match. For -this reason, the assumption is made that the end of the supplied subject string -may not be the true end of the available data, and so, if \z, \Z, \b, \B, -or $ are encountered at the end of the subject, the result is -PCRE_ERROR_PARTIAL, provided that at least one character in the subject has -been inspected. -
--Setting PCRE_PARTIAL_HARD also affects the way UTF-8 and UTF-16 -subject strings are checked for validity. Normally, an invalid sequence -causes the error PCRE_ERROR_BADUTF8 or PCRE_ERROR_BADUTF16. However, in the -special case of a truncated character at the end of the subject, -PCRE_ERROR_SHORTUTF8 or PCRE_ERROR_SHORTUTF16 is returned when -PCRE_PARTIAL_HARD is set. -
--The difference between the two partial matching options can be illustrated by a -pattern such as: -
- /dog(sbody)?/ --This matches either "dog" or "dogsbody", greedily (that is, it prefers the -longer string if possible). If it is matched against the string "dog" with -PCRE_PARTIAL_SOFT, it yields a complete match for "dog". However, if -PCRE_PARTIAL_HARD is set, the result is PCRE_ERROR_PARTIAL. On the other hand, -if the pattern is made ungreedy the result is different: -
- /dog(sbody)??/ --In this case the result is always a complete match because that is found first, -and matching never continues after finding a complete match. It might be easier -to follow this explanation by thinking of the two patterns like this: -
- /dog(sbody)?/ is the same as /dogsbody|dog/ - /dog(sbody)??/ is the same as /dog|dogsbody/ --The second pattern will never match "dogsbody", because it will always find the -shorter match first. - -
-The DFA functions move along the subject string character by character, without -backtracking, searching for all possible matches simultaneously. If the end of -the subject is reached before the end of the pattern, there is the possibility -of a partial match, again provided that at least one character has been -inspected. -
--When PCRE_PARTIAL_SOFT is set, PCRE_ERROR_PARTIAL is returned only if there -have been no complete matches. Otherwise, the complete matches are returned. -However, if PCRE_PARTIAL_HARD is set, a partial match takes precedence over any -complete matches. The portion of the string that was inspected when the longest -partial match was found is set as the first matching string, provided there are -at least two slots in the offsets vector. -
--Because the DFA functions always search for all possible matches, and there is -no difference between greedy and ungreedy repetition, their behaviour is -different from the standard functions when PCRE_PARTIAL_HARD is set. Consider -the string "dog" matched against the ungreedy pattern shown above: -
- /dog(sbody)??/ --Whereas the standard functions stop as soon as they find the complete match for -"dog", the DFA functions also find the partial match for "dogsbody", and so -return that when PCRE_PARTIAL_HARD is set. - -
-If a pattern ends with one of sequences \b or \B, which test for word -boundaries, partial matching with PCRE_PARTIAL_SOFT can give counter-intuitive -results. Consider this pattern: -
- /\bcat\b/ --This matches "cat", provided there is a word boundary at either end. If the -subject string is "the cat", the comparison of the final "t" with a following -character cannot take place, so a partial match is found. However, normal -matching carries on, and \b matches at the end of the subject when the last -character is a letter, so a complete match is found. The result, therefore, is -not PCRE_ERROR_PARTIAL. Using PCRE_PARTIAL_HARD in this case does yield -PCRE_ERROR_PARTIAL, because then the partial match takes precedence. - -
-For releases of PCRE prior to 8.00, because of the way certain internal -optimizations were implemented in the pcre_exec() function, the -PCRE_PARTIAL option (predecessor of PCRE_PARTIAL_SOFT) could not be used with -all patterns. From release 8.00 onwards, the restrictions no longer apply, and -partial matching with can be requested for any pattern. -
--Items that were formerly restricted were repeated single characters and -repeated metasequences. If PCRE_PARTIAL was set for a pattern that did not -conform to the restrictions, pcre_exec() returned the error code -PCRE_ERROR_BADPARTIAL (-13). This error code is no longer in use. The -PCRE_INFO_OKPARTIAL call to pcre_fullinfo() to find out if a compiled -pattern can be used for partial matching now always returns 1. -
--If the escape sequence \P is present in a pcretest data line, the -PCRE_PARTIAL_SOFT option is used for the match. Here is a run of pcretest -that uses the date example quoted above: -
- re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ - data> 25jun04\P - 0: 25jun04 - 1: jun - data> 25dec3\P - Partial match: 23dec3 - data> 3ju\P - Partial match: 3ju - data> 3juj\P - No match - data> j\P - No match --The first data string is matched completely, so pcretest shows the -matched substrings. The remaining four strings do not match the complete -pattern, but the first two are partial matches. Similar output is obtained -if DFA matching is used. - -
-If the escape sequence \P is present more than once in a pcretest data -line, the PCRE_PARTIAL_HARD option is set for the match. -
--When a partial match has been found using a DFA matching function, it is -possible to continue the match by providing additional subject data and calling -the function again with the same compiled regular expression, this time setting -the PCRE_DFA_RESTART option. You must pass the same working space as before, -because this is where details of the previous partial match are stored. Here is -an example using pcretest, using the \R escape sequence to set the -PCRE_DFA_RESTART option (\D specifies the use of the DFA matching function): -
- re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ - data> 23ja\P\D - Partial match: 23ja - data> n05\R\D - 0: n05 --The first call has "23ja" as the subject, and requests partial matching; the -second call has "n05" as the subject for the continued (restarted) match. -Notice that when the match is complete, only the last part is shown; PCRE does -not retain the previously partially-matched string. It is up to the calling -program to do that if it needs to. - -
-That means that, for an unanchored pattern, if a continued match fails, it is -not possible to try again at a new starting point. All this facility is capable -of doing is continuing with the previous match attempt. In the previous -example, if the second set of data is "ug23" the result is no match, even -though there would be a match for "aug23" if the entire string were given at -once. Depending on the application, this may or may not be what you want. -The only way to allow for starting again at the next character is to retain the -matched part of the subject and try a new complete match. -
--You can set the PCRE_PARTIAL_SOFT or PCRE_PARTIAL_HARD options with -PCRE_DFA_RESTART to continue partial matching over multiple segments. This -facility can be used to pass very long subject strings to the DFA matching -functions. -
--From release 8.00, the standard matching functions can also be used to do -multi-segment matching. Unlike the DFA functions, it is not possible to -restart the previous match with a new segment of data. Instead, new data must -be added to the previous subject string, and the entire match re-run, starting -from the point where the partial match occurred. Earlier data can be discarded. -
--It is best to use PCRE_PARTIAL_HARD in this situation, because it does not -treat the end of a segment as the end of the subject when matching \z, \Z, -\b, \B, and $. Consider an unanchored pattern that matches dates: -
- re> /\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d/ - data> The date is 23ja\P\P - Partial match: 23ja --At this stage, an application could discard the text preceding "23ja", add on -text from the next segment, and call the matching function again. Unlike the -DFA matching functions, the entire matching string must always be available, -and the complete matching process occurs for each call, so more memory and more -processing time is needed. - -
-Note: If the pattern contains lookbehind assertions, or \K, or starts -with \b or \B, the string that is returned for a partial match includes -characters that precede the start of what would be returned for a complete -match, because it contains all the characters that were inspected during the -partial match. -
--Certain types of pattern may give problems with multi-segment matching, -whichever matching function is used. -
--1. If the pattern contains a test for the beginning of a line, you need to pass -the PCRE_NOTBOL option when the subject string for any call does start at the -beginning of a line. There is also a PCRE_NOTEOL option, but in practice when -doing multi-segment matching you should be using PCRE_PARTIAL_HARD, which -includes the effect of PCRE_NOTEOL. -
--2. Lookbehind assertions that have already been obeyed are catered for in the -offsets that are returned for a partial match. However a lookbehind assertion -later in the pattern could require even earlier characters to be inspected. You -can handle this case by using the PCRE_INFO_MAXLOOKBEHIND option of the -pcre_fullinfo() or pcre[16|32]_fullinfo() functions to obtain the -length of the longest lookbehind in the pattern. This length is given in -characters, not bytes. If you always retain at least that many characters -before the partially matched string, all should be well. (Of course, near the -start of the subject, fewer characters may be present; in that case all -characters should be retained.) -
--From release 8.33, there is a more accurate way of deciding which characters to -retain. Instead of subtracting the length of the longest lookbehind from the -earliest inspected character (offsets[0]), the match start position -(offsets[2]) should be used, and the next match attempt started at the -offsets[2] character by setting the startoffset argument of -pcre_exec() or pcre_dfa_exec(). -
--For example, if the pattern "(?<=123)abc" is partially -matched against the string "xx123a", the three offset values returned are 2, 6, -and 5. This indicates that the matching process that gave a partial match -started at offset 5, but the characters "123a" were all inspected. The maximum -lookbehind for that pattern is 3, so taking that away from 5 shows that we need -only keep "123a", and the next match attempt can be started at offset 3 (that -is, at "a") when further characters have been added. When the match start is -not the earliest inspected character, pcretest shows it explicitly: -
- re> "(?<=123)abc" - data> xx123a\P\P - Partial match at offset 5: 123a -- -
-3. Because a partial match must always contain at least one character, what -might be considered a partial match of an empty string actually gives a "no -match" result. For example: -
- re> /c(?<=abc)x/ - data> ab\P - No match --If the next segment begins "cx", a match should be found, but this will only -happen if characters from the previous segment are retained. For this reason, a -"no match" result should be interpreted as "partial match of an empty string" -when the pattern contains lookbehinds. - -
-4. Matching a subject string that is split into multiple segments may not -always produce exactly the same result as matching over one single long string, -especially when PCRE_PARTIAL_SOFT is used. The section "Partial Matching and -Word Boundaries" above describes an issue that arises if the pattern ends with -\b or \B. Another kind of difference may occur when there are multiple -matching possibilities, because (for PCRE_PARTIAL_SOFT) a partial match result -is given only when there are no completed matches. This means that as soon as -the shortest match has been found, continuation to a new subject segment is no -longer possible. Consider again this pcretest example: -
- re> /dog(sbody)?/ - data> dogsb\P - 0: dog - data> do\P\D - Partial match: do - data> gsb\R\P\D - 0: g - data> dogsbody\D - 0: dogsbody - 1: dog --The first data line passes the string "dogsb" to a standard matching function, -setting the PCRE_PARTIAL_SOFT option. Although the string is a partial match -for "dogsbody", the result is not PCRE_ERROR_PARTIAL, because the shorter -string "dog" is a complete match. Similarly, when the subject is presented to -a DFA matching function in several parts ("do" and "gsb" being the first two) -the match stops when "dog" has been found, and it is not possible to continue. -On the other hand, if "dogsbody" is presented as a single string, a DFA -matching function finds both matches. - -
-Because of these problems, it is best to use PCRE_PARTIAL_HARD when matching -multi-segment data. The example above then behaves differently: -
- re> /dog(sbody)?/ - data> dogsb\P\P - Partial match: dogsb - data> do\P\D - Partial match: do - data> gsb\R\P\P\D - Partial match: gsb --5. Patterns that contain alternatives at the top level which do not all start -with the same pattern item may not work as expected when PCRE_DFA_RESTART is -used. For example, consider this pattern: -
- 1234|3789 --If the first part of the subject is "ABC123", a partial match of the first -alternative is found at offset 3. There is no partial match for the second -alternative, because such a match does not start at the same point in the -subject string. Attempting to continue with the string "7890" does not yield a -match because only those alternatives that match at one point in the subject -are remembered. The problem arises because the start of the second alternative -matches within the first alternative. There is no problem with anchored -patterns or patterns such as: -
- 1234|ABCD --where no string can be a partial match for both alternatives. This is not a -problem if a standard matching function is used, because the entire match has -to be rerun each time: -
- re> /1234|3789/ - data> ABC123\P\P - Partial match: 123 - data> 1237890 - 0: 3789 --Of course, instead of using PCRE_DFA_RESTART, the same technique of re-running -the entire match can also be used with the DFA matching functions. Another -possibility is to work with two buffers. If a partial match at offset n -in the first buffer is followed by "no match" when PCRE_DFA_RESTART is used on -the second buffer, you can then try a new match starting at offset n+1 in -the first buffer. - -
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 02 July 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrepattern.html b/libs/Pcre16/docs/doc/html/pcrepattern.html deleted file mode 100644 index 96fc72986f..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrepattern.html +++ /dev/null @@ -1,3276 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-The syntax and semantics of the regular expressions that are supported by PCRE -are described in detail below. There is a quick-reference syntax summary in the -pcresyntax -page. PCRE tries to match Perl syntax and semantics as closely as it can. PCRE -also supports some alternative regular expression syntax (which does not -conflict with the Perl syntax) in order to provide some compatibility with -regular expressions in Python, .NET, and Oniguruma. -
--Perl's regular expressions are described in its own documentation, and -regular expressions in general are covered in a number of books, some of which -have copious examples. Jeffrey Friedl's "Mastering Regular Expressions", -published by O'Reilly, covers regular expressions in great detail. This -description of PCRE's regular expressions is intended as reference material. -
--This document discusses the patterns that are supported by PCRE when one its -main matching functions, pcre_exec() (8-bit) or pcre[16|32]_exec() -(16- or 32-bit), is used. PCRE also has alternative matching functions, -pcre_dfa_exec() and pcre[16|32_dfa_exec(), which match using a -different algorithm that is not Perl-compatible. Some of the features discussed -below are not available when DFA matching is used. The advantages and -disadvantages of the alternative functions, and how they differ from the normal -functions, are discussed in the -pcrematching -page. -
--A number of options that can be passed to pcre_compile() can also be set -by special items at the start of a pattern. These are not Perl-compatible, but -are provided to make these options accessible to pattern writers who are not -able to change the program that processes the pattern. Any number of these -items may appear, but they must all be together right at the start of the -pattern string, and the letters must be in upper case. -
--The original operation of PCRE was on strings of one-byte characters. However, -there is now also support for UTF-8 strings in the original library, an -extra library that supports 16-bit and UTF-16 character strings, and a -third library that supports 32-bit and UTF-32 character strings. To use these -features, PCRE must be built to include appropriate support. When using UTF -strings you must either call the compiling function with the PCRE_UTF8, -PCRE_UTF16, or PCRE_UTF32 option, or the pattern must start with one of -these special sequences: -
- (*UTF8) - (*UTF16) - (*UTF32) - (*UTF) --(*UTF) is a generic sequence that can be used with any of the libraries. -Starting a pattern with such a sequence is equivalent to setting the relevant -option. How setting a UTF mode affects pattern matching is mentioned in several -places below. There is also a summary of features in the -pcreunicode -page. - -
-Some applications that allow their users to supply patterns may wish to -restrict them to non-UTF data for security reasons. If the PCRE_NEVER_UTF -option is set at compile time, (*UTF) etc. are not allowed, and their -appearance causes an error. -
--Another special sequence that may appear at the start of a pattern is (*UCP). -This has the same effect as setting the PCRE_UCP option: it causes sequences -such as \d and \w to use Unicode properties to determine character types, -instead of recognizing only characters with codes less than 128 via a lookup -table. -
--If a pattern starts with (*NO_AUTO_POSSESS), it has the same effect as setting -the PCRE_NO_AUTO_POSSESS option at compile time. This stops PCRE from making -quantifiers possessive when what follows cannot match the repeated item. For -example, by default a+b is treated as a++b. For more details, see the -pcreapi -documentation. -
--If a pattern starts with (*NO_START_OPT), it has the same effect as setting the -PCRE_NO_START_OPTIMIZE option either at compile or matching time. This disables -several optimizations for quickly reaching "no match" results. For more -details, see the -pcreapi -documentation. -
--PCRE supports five different conventions for indicating line breaks in -strings: a single CR (carriage return) character, a single LF (linefeed) -character, the two-character sequence CRLF, any of the three preceding, or any -Unicode newline sequence. The -pcreapi -page has -further discussion -about newlines, and shows how to set the newline convention in the -options arguments for the compiling and matching functions. -
--It is also possible to specify a newline convention by starting a pattern -string with one of the following five sequences: -
- (*CR) carriage return - (*LF) linefeed - (*CRLF) carriage return, followed by linefeed - (*ANYCRLF) any of the three above - (*ANY) all Unicode newline sequences --These override the default and the options given to the compiling function. For -example, on a Unix system where LF is the default newline sequence, the pattern -
- (*CR)a.b --changes the convention to CR. That pattern matches "a\nb" because LF is no -longer a newline. If more than one of these settings is present, the last one -is used. - -
-The newline convention affects where the circumflex and dollar assertions are -true. It also affects the interpretation of the dot metacharacter when -PCRE_DOTALL is not set, and the behaviour of \N. However, it does not affect -what the \R escape sequence matches. By default, this is any Unicode newline -sequence, for Perl compatibility. However, this can be changed; see the -description of \R in the section entitled -"Newline sequences" -below. A change of \R setting can be combined with a change of newline -convention. -
--The caller of pcre_exec() can set a limit on the number of times the -internal match() function is called and on the maximum depth of -recursive calls. These facilities are provided to catch runaway matches that -are provoked by patterns with huge matching trees (a typical example is a -pattern with nested unlimited repeats) and to avoid running out of system stack -by too much recursion. When one of these limits is reached, pcre_exec() -gives an error return. The limits can also be set by items at the start of the -pattern of the form -
- (*LIMIT_MATCH=d) - (*LIMIT_RECURSION=d) --where d is any number of decimal digits. However, the value of the setting must -be less than the value set (or defaulted) by the caller of pcre_exec() -for it to have any effect. In other words, the pattern writer can lower the -limits set by the programmer, but not raise them. If there is more than one -setting of one of these limits, the lower value is used. - -
-PCRE can be compiled to run in an environment that uses EBCDIC as its character -code rather than ASCII or Unicode (typically a mainframe system). In the -sections below, character code values are ASCII or Unicode; in an EBCDIC -environment these characters may have different code values, and there are no -code points greater than 255. -
--A regular expression is a pattern that is matched against a subject string from -left to right. Most characters stand for themselves in a pattern, and match the -corresponding characters in the subject. As a trivial example, the pattern -
- The quick brown fox --matches a portion of a subject string that is identical to itself. When -caseless matching is specified (the PCRE_CASELESS option), letters are matched -independently of case. In a UTF mode, PCRE always understands the concept of -case for characters whose values are less than 128, so caseless matching is -always possible. For characters with higher values, the concept of case is -supported if PCRE is compiled with Unicode property support, but not otherwise. -If you want to use caseless matching for characters 128 and above, you must -ensure that PCRE is compiled with Unicode property support as well as with -UTF support. - -
-The power of regular expressions comes from the ability to include alternatives -and repetitions in the pattern. These are encoded in the pattern by the use of -metacharacters, which do not stand for themselves but instead are -interpreted in some special way. -
--There are two different sets of metacharacters: those that are recognized -anywhere in the pattern except within square brackets, and those that are -recognized within square brackets. Outside square brackets, the metacharacters -are as follows: -
- \ general escape character with several uses - ^ assert start of string (or line, in multiline mode) - $ assert end of string (or line, in multiline mode) - . match any character except newline (by default) - [ start character class definition - | start of alternative branch - ( start subpattern - ) end subpattern - ? extends the meaning of ( - also 0 or 1 quantifier - also quantifier minimizer - * 0 or more quantifier - + 1 or more quantifier - also "possessive quantifier" - { start min/max quantifier --Part of a pattern that is in square brackets is called a "character class". In -a character class the only metacharacters are: -
- \ general escape character - ^ negate the class, but only if the first character - - indicates character range - [ POSIX character class (only if followed by POSIX syntax) - ] terminates the character class --The following sections describe the use of each of the metacharacters. - -
-The backslash character has several uses. Firstly, if it is followed by a -character that is not a number or a letter, it takes away any special meaning -that character may have. This use of backslash as an escape character applies -both inside and outside character classes. -
--For example, if you want to match a * character, you write \* in the pattern. -This escaping action applies whether or not the following character would -otherwise be interpreted as a metacharacter, so it is always safe to precede a -non-alphanumeric with backslash to specify that it stands for itself. In -particular, if you want to match a backslash, you write \\. -
--In a UTF mode, only ASCII numbers and letters have any special meaning after a -backslash. All other characters (in particular, those whose codepoints are -greater than 127) are treated as literals. -
--If a pattern is compiled with the PCRE_EXTENDED option, most white space in the -pattern (other than in a character class), and characters between a # outside a -character class and the next newline, inclusive, are ignored. An escaping -backslash can be used to include a white space or # character as part of the -pattern. -
--If you want to remove the special meaning from a sequence of characters, you -can do so by putting them between \Q and \E. This is different from Perl in -that $ and @ are handled as literals in \Q...\E sequences in PCRE, whereas in -Perl, $ and @ cause variable interpolation. Note the following examples: -
- Pattern PCRE matches Perl matches - - \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz - \Qabc\$xyz\E abc\$xyz abc\$xyz - \Qabc\E\$\Qxyz\E abc$xyz abc$xyz --The \Q...\E sequence is recognized both inside and outside character classes. -An isolated \E that is not preceded by \Q is ignored. If \Q is not followed -by \E later in the pattern, the literal interpretation continues to the end of -the pattern (that is, \E is assumed at the end). If the isolated \Q is inside -a character class, this causes an error, because the character class is not -terminated. - -
-A second use of backslash provides a way of encoding non-printing characters -in patterns in a visible manner. There is no restriction on the appearance of -non-printing characters, apart from the binary zero that terminates a pattern, -but when a pattern is being prepared by text editing, it is often easier to use -one of the following escape sequences than the binary character it represents. -In an ASCII or Unicode environment, these escapes are as follows: -
- \a alarm, that is, the BEL character (hex 07) - \cx "control-x", where x is any ASCII character - \e escape (hex 1B) - \f form feed (hex 0C) - \n linefeed (hex 0A) - \r carriage return (hex 0D) - \t tab (hex 09) - \0dd character with octal code 0dd - \ddd character with octal code ddd, or back reference - \o{ddd..} character with octal code ddd.. - \xhh character with hex code hh - \x{hhh..} character with hex code hhh.. (non-JavaScript mode) - \uhhhh character with hex code hhhh (JavaScript mode only) --The precise effect of \cx on ASCII characters is as follows: if x is a lower -case letter, it is converted to upper case. Then bit 6 of the character (hex -40) is inverted. Thus \cA to \cZ become hex 01 to hex 1A (A is 41, Z is 5A), -but \c{ becomes hex 3B ({ is 7B), and \c; becomes hex 7B (; is 3B). If the -data item (byte or 16-bit value) following \c has a value greater than 127, a -compile-time error occurs. This locks out non-ASCII characters in all modes. - -
-When PCRE is compiled in EBCDIC mode, \a, \e, \f, \n, \r, and \t -generate the appropriate EBCDIC code values. The \c escape is processed -as specified for Perl in the perlebcdic document. The only characters -that are allowed after \c are A-Z, a-z, or one of @, [, \, ], ^, _, or ?. Any -other character provokes a compile-time error. The sequence \c@ encodes -character code 0; after \c the letters (in either case) encode characters 1-26 -(hex 01 to hex 1A); [, \, ], ^, and _ encode characters 27-31 (hex 1B to hex -1F), and \c? becomes either 255 (hex FF) or 95 (hex 5F). -
--Thus, apart from \c?, these escapes generate the same character code values as -they do in an ASCII environment, though the meanings of the values mostly -differ. For example, \cG always generates code value 7, which is BEL in ASCII -but DEL in EBCDIC. -
--The sequence \c? generates DEL (127, hex 7F) in an ASCII environment, but -because 127 is not a control character in EBCDIC, Perl makes it generate the -APC character. Unfortunately, there are several variants of EBCDIC. In most of -them the APC character has the value 255 (hex FF), but in the one Perl calls -POSIX-BC its value is 95 (hex 5F). If certain other characters have POSIX-BC -values, PCRE makes \c? generate 95; otherwise it generates 255. -
--After \0 up to two further octal digits are read. If there are fewer than two -digits, just those that are present are used. Thus the sequence \0\x\015 -specifies two binary zeros followed by a CR character (code value 13). Make -sure you supply two digits after the initial zero if the pattern character that -follows is itself an octal digit. -
--The escape \o must be followed by a sequence of octal digits, enclosed in -braces. An error occurs if this is not the case. This escape is a recent -addition to Perl; it provides way of specifying character code points as octal -numbers greater than 0777, and it also allows octal numbers and back references -to be unambiguously specified. -
--For greater clarity and unambiguity, it is best to avoid following \ by a -digit greater than zero. Instead, use \o{} or \x{} to specify character -numbers, and \g{} to specify back references. The following paragraphs -describe the old, ambiguous syntax. -
--The handling of a backslash followed by a digit other than 0 is complicated, -and Perl has changed in recent releases, causing PCRE also to change. Outside a -character class, PCRE reads the digit and any following digits as a decimal -number. If the number is less than 8, or if there have been at least that many -previous capturing left parentheses in the expression, the entire sequence is -taken as a back reference. A description of how this works is given -later, -following the discussion of -parenthesized subpatterns. -
--Inside a character class, or if the decimal number following \ is greater than -7 and there have not been that many capturing subpatterns, PCRE handles \8 and -\9 as the literal characters "8" and "9", and otherwise re-reads up to three -octal digits following the backslash, using them to generate a data character. -Any subsequent digits stand for themselves. For example: -
- \040 is another way of writing an ASCII space - \40 is the same, provided there are fewer than 40 previous capturing subpatterns - \7 is always a back reference - \11 might be a back reference, or another way of writing a tab - \011 is always a tab - \0113 is a tab followed by the character "3" - \113 might be a back reference, otherwise the character with octal code 113 - \377 might be a back reference, otherwise the value 255 (decimal) - \81 is either a back reference, or the two characters "8" and "1" --Note that octal values of 100 or greater that are specified using this syntax -must not be introduced by a leading zero, because no more than three octal -digits are ever read. - -
-By default, after \x that is not followed by {, from zero to two hexadecimal -digits are read (letters can be in upper or lower case). Any number of -hexadecimal digits may appear between \x{ and }. If a character other than -a hexadecimal digit appears between \x{ and }, or if there is no terminating -}, an error occurs. -
--If the PCRE_JAVASCRIPT_COMPAT option is set, the interpretation of \x is -as just described only when it is followed by two hexadecimal digits. -Otherwise, it matches a literal "x" character. In JavaScript mode, support for -code points greater than 256 is provided by \u, which must be followed by -four hexadecimal digits; otherwise it matches a literal "u" character. -
--Characters whose value is less than 256 can be defined by either of the two -syntaxes for \x (or by \u in JavaScript mode). There is no difference in the -way they are handled. For example, \xdc is exactly the same as \x{dc} (or -\u00dc in JavaScript mode). -
--Characters that are specified using octal or hexadecimal numbers are -limited to certain values, as follows: -
- 8-bit non-UTF mode less than 0x100 - 8-bit UTF-8 mode less than 0x10ffff and a valid codepoint - 16-bit non-UTF mode less than 0x10000 - 16-bit UTF-16 mode less than 0x10ffff and a valid codepoint - 32-bit non-UTF mode less than 0x100000000 - 32-bit UTF-32 mode less than 0x10ffff and a valid codepoint --Invalid Unicode codepoints are the range 0xd800 to 0xdfff (the so-called -"surrogate" codepoints), and 0xffef. - -
-All the sequences that define a single character value can be used both inside -and outside character classes. In addition, inside a character class, \b is -interpreted as the backspace character (hex 08). -
--\N is not allowed in a character class. \B, \R, and \X are not special -inside a character class. Like other unrecognized escape sequences, they are -treated as the literal characters "B", "R", and "X" by default, but cause an -error if the PCRE_EXTRA option is set. Outside a character class, these -sequences have different meanings. -
--In Perl, the sequences \l, \L, \u, and \U are recognized by its string -handler and used to modify the case of following characters. By default, PCRE -does not support these escape sequences. However, if the PCRE_JAVASCRIPT_COMPAT -option is set, \U matches a "U" character, and \u can be used to define a -character by code point, as described in the previous section. -
--The sequence \g followed by an unsigned or a negative number, optionally -enclosed in braces, is an absolute or relative back reference. A named back -reference can be coded as \g{name}. Back references are discussed -later, -following the discussion of -parenthesized subpatterns. -
--For compatibility with Oniguruma, the non-Perl syntax \g followed by a name or -a number enclosed either in angle brackets or single quotes, is an alternative -syntax for referencing a subpattern as a "subroutine". Details are discussed -later. -Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are not -synonymous. The former is a back reference; the latter is a -subroutine -call. -
--Another use of backslash is for specifying generic character types: -
- \d any decimal digit - \D any character that is not a decimal digit - \h any horizontal white space character - \H any character that is not a horizontal white space character - \s any white space character - \S any character that is not a white space character - \v any vertical white space character - \V any character that is not a vertical white space character - \w any "word" character - \W any "non-word" character --There is also the single sequence \N, which matches a non-newline character. -This is the same as -the "." metacharacter -when PCRE_DOTALL is not set. Perl also uses \N to match characters by name; -PCRE does not support this. - -
-Each pair of lower and upper case escape sequences partitions the complete set -of characters into two disjoint sets. Any given character matches one, and only -one, of each pair. The sequences can appear both inside and outside character -classes. They each match one character of the appropriate type. If the current -matching point is at the end of the subject string, all of them fail, because -there is no character to match. -
--For compatibility with Perl, \s did not used to match the VT character (code -11), which made it different from the the POSIX "space" class. However, Perl -added VT at release 5.18, and PCRE followed suit at release 8.34. The default -\s characters are now HT (9), LF (10), VT (11), FF (12), CR (13), and space -(32), which are defined as white space in the "C" locale. This list may vary if -locale-specific matching is taking place. For example, in some locales the -"non-breaking space" character (\xA0) is recognized as white space, and in -others the VT character is not. -
--A "word" character is an underscore or any character that is a letter or digit. -By default, the definition of letters and digits is controlled by PCRE's -low-valued character tables, and may vary if locale-specific matching is taking -place (see -"Locale support" -in the -pcreapi -page). For example, in a French locale such as "fr_FR" in Unix-like systems, -or "french" in Windows, some character codes greater than 127 are used for -accented letters, and these are then matched by \w. The use of locales with -Unicode is discouraged. -
--By default, characters whose code points are greater than 127 never match \d, -\s, or \w, and always match \D, \S, and \W, although this may vary for -characters in the range 128-255 when locale-specific matching is happening. -These escape sequences retain their original meanings from before Unicode -support was available, mainly for efficiency reasons. If PCRE is compiled with -Unicode property support, and the PCRE_UCP option is set, the behaviour is -changed so that Unicode properties are used to determine character types, as -follows: -
- \d any character that matches \p{Nd} (decimal digit) - \s any character that matches \p{Z} or \h or \v - \w any character that matches \p{L} or \p{N}, plus underscore --The upper case escapes match the inverse sets of characters. Note that \d -matches only decimal digits, whereas \w matches any Unicode digit, as well as -any Unicode letter, and underscore. Note also that PCRE_UCP affects \b, and -\B because they are defined in terms of \w and \W. Matching these sequences -is noticeably slower when PCRE_UCP is set. - -
-The sequences \h, \H, \v, and \V are features that were added to Perl at -release 5.10. In contrast to the other sequences, which match only ASCII -characters by default, these always match certain high-valued code points, -whether or not PCRE_UCP is set. The horizontal space characters are: -
- U+0009 Horizontal tab (HT) - U+0020 Space - U+00A0 Non-break space - U+1680 Ogham space mark - U+180E Mongolian vowel separator - U+2000 En quad - U+2001 Em quad - U+2002 En space - U+2003 Em space - U+2004 Three-per-em space - U+2005 Four-per-em space - U+2006 Six-per-em space - U+2007 Figure space - U+2008 Punctuation space - U+2009 Thin space - U+200A Hair space - U+202F Narrow no-break space - U+205F Medium mathematical space - U+3000 Ideographic space --The vertical space characters are: -
- U+000A Linefeed (LF) - U+000B Vertical tab (VT) - U+000C Form feed (FF) - U+000D Carriage return (CR) - U+0085 Next line (NEL) - U+2028 Line separator - U+2029 Paragraph separator --In 8-bit, non-UTF-8 mode, only the characters with codepoints less than 256 are -relevant. - -
-Outside a character class, by default, the escape sequence \R matches any -Unicode newline sequence. In 8-bit non-UTF-8 mode \R is equivalent to the -following: -
- (?>\r\n|\n|\x0b|\f|\r|\x85) --This is an example of an "atomic group", details of which are given -below. -This particular group matches either the two-character sequence CR followed by -LF, or one of the single characters LF (linefeed, U+000A), VT (vertical tab, -U+000B), FF (form feed, U+000C), CR (carriage return, U+000D), or NEL (next -line, U+0085). The two-character sequence is treated as a single unit that -cannot be split. - -
-In other modes, two additional characters whose codepoints are greater than 255 -are added: LS (line separator, U+2028) and PS (paragraph separator, U+2029). -Unicode character property support is not needed for these characters to be -recognized. -
--It is possible to restrict \R to match only CR, LF, or CRLF (instead of the -complete set of Unicode line endings) by setting the option PCRE_BSR_ANYCRLF -either at compile time or when the pattern is matched. (BSR is an abbrevation -for "backslash R".) This can be made the default when PCRE is built; if this is -the case, the other behaviour can be requested via the PCRE_BSR_UNICODE option. -It is also possible to specify these settings by starting a pattern string with -one of the following sequences: -
- (*BSR_ANYCRLF) CR, LF, or CRLF only - (*BSR_UNICODE) any Unicode newline sequence --These override the default and the options given to the compiling function, but -they can themselves be overridden by options given to a matching function. Note -that these special settings, which are not Perl-compatible, are recognized only -at the very start of a pattern, and that they must be in upper case. If more -than one of them is present, the last one is used. They can be combined with a -change of newline convention; for example, a pattern can start with: -
- (*ANY)(*BSR_ANYCRLF) --They can also be combined with the (*UTF8), (*UTF16), (*UTF32), (*UTF) or -(*UCP) special sequences. Inside a character class, \R is treated as an -unrecognized escape sequence, and so matches the letter "R" by default, but -causes an error if PCRE_EXTRA is set. - -
-When PCRE is built with Unicode character property support, three additional -escape sequences that match characters with specific properties are available. -When in 8-bit non-UTF-8 mode, these sequences are of course limited to testing -characters whose codepoints are less than 256, but they do work in this mode. -The extra escape sequences are: -
- \p{xx} a character with the xx property - \P{xx} a character without the xx property - \X a Unicode extended grapheme cluster --The property names represented by xx above are limited to the Unicode -script names, the general category properties, "Any", which matches any -character (including newline), and some special PCRE properties (described -in the -next section). -Other Perl properties such as "InMusicalSymbols" are not currently supported by -PCRE. Note that \P{Any} does not match any characters, so always causes a -match failure. - -
-Sets of Unicode characters are defined as belonging to certain scripts. A -character from one of these sets can be matched using a script name. For -example: -
- \p{Greek} - \P{Han} --Those that are not part of an identified script are lumped together as -"Common". The current list of scripts is: - -
-Arabic, -Armenian, -Avestan, -Balinese, -Bamum, -Bassa_Vah, -Batak, -Bengali, -Bopomofo, -Brahmi, -Braille, -Buginese, -Buhid, -Canadian_Aboriginal, -Carian, -Caucasian_Albanian, -Chakma, -Cham, -Cherokee, -Common, -Coptic, -Cuneiform, -Cypriot, -Cyrillic, -Deseret, -Devanagari, -Duployan, -Egyptian_Hieroglyphs, -Elbasan, -Ethiopic, -Georgian, -Glagolitic, -Gothic, -Grantha, -Greek, -Gujarati, -Gurmukhi, -Han, -Hangul, -Hanunoo, -Hebrew, -Hiragana, -Imperial_Aramaic, -Inherited, -Inscriptional_Pahlavi, -Inscriptional_Parthian, -Javanese, -Kaithi, -Kannada, -Katakana, -Kayah_Li, -Kharoshthi, -Khmer, -Khojki, -Khudawadi, -Lao, -Latin, -Lepcha, -Limbu, -Linear_A, -Linear_B, -Lisu, -Lycian, -Lydian, -Mahajani, -Malayalam, -Mandaic, -Manichaean, -Meetei_Mayek, -Mende_Kikakui, -Meroitic_Cursive, -Meroitic_Hieroglyphs, -Miao, -Modi, -Mongolian, -Mro, -Myanmar, -Nabataean, -New_Tai_Lue, -Nko, -Ogham, -Ol_Chiki, -Old_Italic, -Old_North_Arabian, -Old_Permic, -Old_Persian, -Old_South_Arabian, -Old_Turkic, -Oriya, -Osmanya, -Pahawh_Hmong, -Palmyrene, -Pau_Cin_Hau, -Phags_Pa, -Phoenician, -Psalter_Pahlavi, -Rejang, -Runic, -Samaritan, -Saurashtra, -Sharada, -Shavian, -Siddham, -Sinhala, -Sora_Sompeng, -Sundanese, -Syloti_Nagri, -Syriac, -Tagalog, -Tagbanwa, -Tai_Le, -Tai_Tham, -Tai_Viet, -Takri, -Tamil, -Telugu, -Thaana, -Thai, -Tibetan, -Tifinagh, -Tirhuta, -Ugaritic, -Vai, -Warang_Citi, -Yi. -
--Each character has exactly one Unicode general category property, specified by -a two-letter abbreviation. For compatibility with Perl, negation can be -specified by including a circumflex between the opening brace and the property -name. For example, \p{^Lu} is the same as \P{Lu}. -
--If only one letter is specified with \p or \P, it includes all the general -category properties that start with that letter. In this case, in the absence -of negation, the curly brackets in the escape sequence are optional; these two -examples have the same effect: -
- \p{L} - \pL --The following general category property codes are supported: -
- C Other - Cc Control - Cf Format - Cn Unassigned - Co Private use - Cs Surrogate - - L Letter - Ll Lower case letter - Lm Modifier letter - Lo Other letter - Lt Title case letter - Lu Upper case letter - - M Mark - Mc Spacing mark - Me Enclosing mark - Mn Non-spacing mark - - N Number - Nd Decimal number - Nl Letter number - No Other number - - P Punctuation - Pc Connector punctuation - Pd Dash punctuation - Pe Close punctuation - Pf Final punctuation - Pi Initial punctuation - Po Other punctuation - Ps Open punctuation - - S Symbol - Sc Currency symbol - Sk Modifier symbol - Sm Mathematical symbol - So Other symbol - - Z Separator - Zl Line separator - Zp Paragraph separator - Zs Space separator --The special property L& is also supported: it matches a character that has -the Lu, Ll, or Lt property, in other words, a letter that is not classified as -a modifier or "other". - -
-The Cs (Surrogate) property applies only to characters in the range U+D800 to -U+DFFF. Such characters are not valid in Unicode strings and so -cannot be tested by PCRE, unless UTF validity checking has been turned off -(see the discussion of PCRE_NO_UTF8_CHECK, PCRE_NO_UTF16_CHECK and -PCRE_NO_UTF32_CHECK in the -pcreapi -page). Perl does not support the Cs property. -
--The long synonyms for property names that Perl supports (such as \p{Letter}) -are not supported by PCRE, nor is it permitted to prefix any of these -properties with "Is". -
--No character that is in the Unicode table has the Cn (unassigned) property. -Instead, this property is assumed for any code point that is not in the -Unicode table. -
--Specifying caseless matching does not affect these escape sequences. For -example, \p{Lu} always matches only upper case letters. This is different from -the behaviour of current versions of Perl. -
--Matching characters by Unicode property is not fast, because PCRE has to do a -multistage table lookup in order to find a character's property. That is why -the traditional escape sequences such as \d and \w do not use Unicode -properties in PCRE by default, though you can make them do so by setting the -PCRE_UCP option or by starting the pattern with (*UCP). -
--The \X escape matches any number of Unicode characters that form an "extended -grapheme cluster", and treats the sequence as an atomic group -(see below). -Up to and including release 8.31, PCRE matched an earlier, simpler definition -that was equivalent to -
- (?>\PM\pM*) --That is, it matched a character without the "mark" property, followed by zero -or more characters with the "mark" property. Characters with the "mark" -property are typically non-spacing accents that affect the preceding character. - -
-This simple definition was extended in Unicode to include more complicated -kinds of composite character by giving each character a grapheme breaking -property, and creating rules that use these properties to define the boundaries -of extended grapheme clusters. In releases of PCRE later than 8.31, \X matches -one of these clusters. -
--\X always matches at least one character. Then it decides whether to add -additional characters according to the following rules for ending a cluster: -
--1. End at the end of the subject string. -
--2. Do not end between CR and LF; otherwise end after any control character. -
--3. Do not break Hangul (a Korean script) syllable sequences. Hangul characters -are of five types: L, V, T, LV, and LVT. An L character may be followed by an -L, V, LV, or LVT character; an LV or V character may be followed by a V or T -character; an LVT or T character may be follwed only by a T character. -
--4. Do not end before extending characters or spacing marks. Characters with -the "mark" property always have the "extend" grapheme breaking property. -
--5. Do not end after prepend characters. -
--6. Otherwise, end the cluster. -
--As well as the standard Unicode properties described above, PCRE supports four -more that make it possible to convert traditional escape sequences such as \w -and \s to use Unicode properties. PCRE uses these non-standard, non-Perl -properties internally when PCRE_UCP is set. However, they may also be used -explicitly. These properties are: -
- Xan Any alphanumeric character - Xps Any POSIX space character - Xsp Any Perl space character - Xwd Any Perl "word" character --Xan matches characters that have either the L (letter) or the N (number) -property. Xps matches the characters tab, linefeed, vertical tab, form feed, or -carriage return, and any other character that has the Z (separator) property. -Xsp is the same as Xps; it used to exclude vertical tab, for Perl -compatibility, but Perl changed, and so PCRE followed at release 8.34. Xwd -matches the same characters as Xan, plus underscore. - -
-There is another non-standard property, Xuc, which matches any character that -can be represented by a Universal Character Name in C++ and other programming -languages. These are the characters $, @, ` (grave accent), and all characters -with Unicode code points greater than or equal to U+00A0, except for the -surrogates U+D800 to U+DFFF. Note that most base (ASCII) characters are -excluded. (Universal Character Names are of the form \uHHHH or \UHHHHHHHH -where H is a hexadecimal digit. Note that the Xuc property does not match these -sequences but the characters that they represent.) -
--The escape sequence \K causes any previously matched characters not to be -included in the final matched sequence. For example, the pattern: -
- foo\Kbar --matches "foobar", but reports that it has matched "bar". This feature is -similar to a lookbehind assertion -(described below). -However, in this case, the part of the subject before the real match does not -have to be of fixed length, as lookbehind assertions do. The use of \K does -not interfere with the setting of -captured substrings. -For example, when the pattern -
- (foo)\Kbar --matches "foobar", the first substring is still set to "foo". - -
-Perl documents that the use of \K within assertions is "not well defined". In -PCRE, \K is acted upon when it occurs inside positive assertions, but is -ignored in negative assertions. Note that when a pattern such as (?=ab\K) -matches, the reported start of the match can be greater than the end of the -match. -
--The final use of backslash is for certain simple assertions. An assertion -specifies a condition that has to be met at a particular point in a match, -without consuming any characters from the subject string. The use of -subpatterns for more complicated assertions is described -below. -The backslashed assertions are: -
- \b matches at a word boundary - \B matches when not at a word boundary - \A matches at the start of the subject - \Z matches at the end of the subject - also matches before a newline at the end of the subject - \z matches only at the end of the subject - \G matches at the first matching position in the subject --Inside a character class, \b has a different meaning; it matches the backspace -character. If any other of these assertions appears in a character class, by -default it matches the corresponding literal character (for example, \B -matches the letter B). However, if the PCRE_EXTRA option is set, an "invalid -escape sequence" error is generated instead. - -
-A word boundary is a position in the subject string where the current character -and the previous character do not both match \w or \W (i.e. one matches -\w and the other matches \W), or the start or end of the string if the -first or last character matches \w, respectively. In a UTF mode, the meanings -of \w and \W can be changed by setting the PCRE_UCP option. When this is -done, it also affects \b and \B. Neither PCRE nor Perl has a separate "start -of word" or "end of word" metasequence. However, whatever follows \b normally -determines which it is. For example, the fragment \ba matches "a" at the start -of a word. -
--The \A, \Z, and \z assertions differ from the traditional circumflex and -dollar (described in the next section) in that they only ever match at the very -start and end of the subject string, whatever options are set. Thus, they are -independent of multiline mode. These three assertions are not affected by the -PCRE_NOTBOL or PCRE_NOTEOL options, which affect only the behaviour of the -circumflex and dollar metacharacters. However, if the startoffset -argument of pcre_exec() is non-zero, indicating that matching is to start -at a point other than the beginning of the subject, \A can never match. The -difference between \Z and \z is that \Z matches before a newline at the end -of the string as well as at the very end, whereas \z matches only at the end. -
--The \G assertion is true only when the current matching position is at the -start point of the match, as specified by the startoffset argument of -pcre_exec(). It differs from \A when the value of startoffset is -non-zero. By calling pcre_exec() multiple times with appropriate -arguments, you can mimic Perl's /g option, and it is in this kind of -implementation where \G can be useful. -
--Note, however, that PCRE's interpretation of \G, as the start of the current -match, is subtly different from Perl's, which defines it as the end of the -previous match. In Perl, these can be different when the previously matched -string was empty. Because PCRE does just one match at a time, it cannot -reproduce this behaviour. -
--If all the alternatives of a pattern begin with \G, the expression is anchored -to the starting match position, and the "anchored" flag is set in the compiled -regular expression. -
--The circumflex and dollar metacharacters are zero-width assertions. That is, -they test for a particular condition being true without consuming any -characters from the subject string. -
--Outside a character class, in the default matching mode, the circumflex -character is an assertion that is true only if the current matching point is at -the start of the subject string. If the startoffset argument of -pcre_exec() is non-zero, circumflex can never match if the PCRE_MULTILINE -option is unset. Inside a character class, circumflex has an entirely different -meaning -(see below). -
--Circumflex need not be the first character of the pattern if a number of -alternatives are involved, but it should be the first thing in each alternative -in which it appears if the pattern is ever to match that branch. If all -possible alternatives start with a circumflex, that is, if the pattern is -constrained to match only at the start of the subject, it is said to be an -"anchored" pattern. (There are also other constructs that can cause a pattern -to be anchored.) -
--The dollar character is an assertion that is true only if the current matching -point is at the end of the subject string, or immediately before a newline at -the end of the string (by default). Note, however, that it does not actually -match the newline. Dollar need not be the last character of the pattern if a -number of alternatives are involved, but it should be the last item in any -branch in which it appears. Dollar has no special meaning in a character class. -
--The meaning of dollar can be changed so that it matches only at the very end of -the string, by setting the PCRE_DOLLAR_ENDONLY option at compile time. This -does not affect the \Z assertion. -
--The meanings of the circumflex and dollar characters are changed if the -PCRE_MULTILINE option is set. When this is the case, a circumflex matches -immediately after internal newlines as well as at the start of the subject -string. It does not match after a newline that ends the string. A dollar -matches before any newlines in the string, as well as at the very end, when -PCRE_MULTILINE is set. When newline is specified as the two-character -sequence CRLF, isolated CR and LF characters do not indicate newlines. -
--For example, the pattern /^abc$/ matches the subject string "def\nabc" (where -\n represents a newline) in multiline mode, but not otherwise. Consequently, -patterns that are anchored in single line mode because all branches start with -^ are not anchored in multiline mode, and a match for circumflex is possible -when the startoffset argument of pcre_exec() is non-zero. The -PCRE_DOLLAR_ENDONLY option is ignored if PCRE_MULTILINE is set. -
--Note that the sequences \A, \Z, and \z can be used to match the start and -end of the subject in both modes, and if all branches of a pattern start with -\A it is always anchored, whether or not PCRE_MULTILINE is set. -
--Outside a character class, a dot in the pattern matches any one character in -the subject string except (by default) a character that signifies the end of a -line. -
--When a line ending is defined as a single character, dot never matches that -character; when the two-character sequence CRLF is used, dot does not match CR -if it is immediately followed by LF, but otherwise it matches all characters -(including isolated CRs and LFs). When any Unicode line endings are being -recognized, dot does not match CR or LF or any of the other line ending -characters. -
--The behaviour of dot with regard to newlines can be changed. If the PCRE_DOTALL -option is set, a dot matches any one character, without exception. If the -two-character sequence CRLF is present in the subject string, it takes two dots -to match it. -
--The handling of dot is entirely independent of the handling of circumflex and -dollar, the only relationship being that they both involve newlines. Dot has no -special meaning in a character class. -
--The escape sequence \N behaves like a dot, except that it is not affected by -the PCRE_DOTALL option. In other words, it matches any character except one -that signifies the end of a line. Perl also uses \N to match characters by -name; PCRE does not support this. -
--Outside a character class, the escape sequence \C matches any one data unit, -whether or not a UTF mode is set. In the 8-bit library, one data unit is one -byte; in the 16-bit library it is a 16-bit unit; in the 32-bit library it is -a 32-bit unit. Unlike a dot, \C always -matches line-ending characters. The feature is provided in Perl in order to -match individual bytes in UTF-8 mode, but it is unclear how it can usefully be -used. Because \C breaks up characters into individual data units, matching one -unit with \C in a UTF mode means that the rest of the string may start with a -malformed UTF character. This has undefined results, because PCRE assumes that -it is dealing with valid UTF strings (and by default it checks this at the -start of processing unless the PCRE_NO_UTF8_CHECK, PCRE_NO_UTF16_CHECK or -PCRE_NO_UTF32_CHECK option is used). -
--PCRE does not allow \C to appear in lookbehind assertions -(described below) -in a UTF mode, because this would make it impossible to calculate the length of -the lookbehind. -
--In general, the \C escape sequence is best avoided. However, one -way of using it that avoids the problem of malformed UTF characters is to use a -lookahead to check the length of the next character, as in this pattern, which -could be used with a UTF-8 string (ignore white space and line breaks): -
- (?| (?=[\x00-\x7f])(\C) | - (?=[\x80-\x{7ff}])(\C)(\C) | - (?=[\x{800}-\x{ffff}])(\C)(\C)(\C) | - (?=[\x{10000}-\x{1fffff}])(\C)(\C)(\C)(\C)) --A group that starts with (?| resets the capturing parentheses numbers in each -alternative (see -"Duplicate Subpattern Numbers" -below). The assertions at the start of each branch check the next UTF-8 -character for values whose encoding uses 1, 2, 3, or 4 bytes, respectively. The -character's individual bytes are then captured by the appropriate number of -groups. - -
-An opening square bracket introduces a character class, terminated by a closing -square bracket. A closing square bracket on its own is not special by default. -However, if the PCRE_JAVASCRIPT_COMPAT option is set, a lone closing square -bracket causes a compile-time error. If a closing square bracket is required as -a member of the class, it should be the first data character in the class -(after an initial circumflex, if present) or escaped with a backslash. -
--A character class matches a single character in the subject. In a UTF mode, the -character may be more than one data unit long. A matched character must be in -the set of characters defined by the class, unless the first character in the -class definition is a circumflex, in which case the subject character must not -be in the set defined by the class. If a circumflex is actually required as a -member of the class, ensure it is not the first character, or escape it with a -backslash. -
--For example, the character class [aeiou] matches any lower case vowel, while -[^aeiou] matches any character that is not a lower case vowel. Note that a -circumflex is just a convenient notation for specifying the characters that -are in the class by enumerating those that are not. A class that starts with a -circumflex is not an assertion; it still consumes a character from the subject -string, and therefore it fails if the current pointer is at the end of the -string. -
--In UTF-8 (UTF-16, UTF-32) mode, characters with values greater than 255 (0xffff) -can be included in a class as a literal string of data units, or by using the -\x{ escaping mechanism. -
--When caseless matching is set, any letters in a class represent both their -upper case and lower case versions, so for example, a caseless [aeiou] matches -"A" as well as "a", and a caseless [^aeiou] does not match "A", whereas a -caseful version would. In a UTF mode, PCRE always understands the concept of -case for characters whose values are less than 128, so caseless matching is -always possible. For characters with higher values, the concept of case is -supported if PCRE is compiled with Unicode property support, but not otherwise. -If you want to use caseless matching in a UTF mode for characters 128 and -above, you must ensure that PCRE is compiled with Unicode property support as -well as with UTF support. -
--Characters that might indicate line breaks are never treated in any special way -when matching character classes, whatever line-ending sequence is in use, and -whatever setting of the PCRE_DOTALL and PCRE_MULTILINE options is used. A class -such as [^a] always matches one of these characters. -
--The minus (hyphen) character can be used to specify a range of characters in a -character class. For example, [d-m] matches any letter between d and m, -inclusive. If a minus character is required in a class, it must be escaped with -a backslash or appear in a position where it cannot be interpreted as -indicating a range, typically as the first or last character in the class, or -immediately after a range. For example, [b-d-z] matches letters in the range b -to d, a hyphen character, or z. -
--It is not possible to have the literal character "]" as the end character of a -range. A pattern such as [W-]46] is interpreted as a class of two characters -("W" and "-") followed by a literal string "46]", so it would match "W46]" or -"-46]". However, if the "]" is escaped with a backslash it is interpreted as -the end of range, so [W-\]46] is interpreted as a class containing a range -followed by two other characters. The octal or hexadecimal representation of -"]" can also be used to end a range. -
--An error is generated if a POSIX character class (see below) or an escape -sequence other than one that defines a single character appears at a point -where a range ending character is expected. For example, [z-\xff] is valid, -but [A-\d] and [A-[:digit:]] are not. -
--Ranges operate in the collating sequence of character values. They can also be -used for characters specified numerically, for example [\000-\037]. Ranges -can include any characters that are valid for the current mode. -
--If a range that includes letters is used when caseless matching is set, it -matches the letters in either case. For example, [W-c] is equivalent to -[][\\^_`wxyzabc], matched caselessly, and in a non-UTF mode, if character -tables for a French locale are in use, [\xc8-\xcb] matches accented E -characters in both cases. In UTF modes, PCRE supports the concept of case for -characters with values greater than 128 only when it is compiled with Unicode -property support. -
--The character escape sequences \d, \D, \h, \H, \p, \P, \s, \S, \v, -\V, \w, and \W may appear in a character class, and add the characters that -they match to the class. For example, [\dABCDEF] matches any hexadecimal -digit. In UTF modes, the PCRE_UCP option affects the meanings of \d, \s, \w -and their upper case partners, just as it does when they appear outside a -character class, as described in the section entitled -"Generic character types" -above. The escape sequence \b has a different meaning inside a character -class; it matches the backspace character. The sequences \B, \N, \R, and \X -are not special inside a character class. Like any other unrecognized escape -sequences, they are treated as the literal characters "B", "N", "R", and "X" by -default, but cause an error if the PCRE_EXTRA option is set. -
--A circumflex can conveniently be used with the upper case character types to -specify a more restricted set of characters than the matching lower case type. -For example, the class [^\W_] matches any letter or digit, but not underscore, -whereas [\w] includes underscore. A positive character class should be read as -"something OR something OR ..." and a negative class as "NOT something AND NOT -something AND NOT ...". -
--The only metacharacters that are recognized in character classes are backslash, -hyphen (only where it can be interpreted as specifying a range), circumflex -(only at the start), opening square bracket (only when it can be interpreted as -introducing a POSIX class name, or for a special compatibility feature - see -the next two sections), and the terminating closing square bracket. However, -escaping other non-alphanumeric characters does no harm. -
--Perl supports the POSIX notation for character classes. This uses names -enclosed by [: and :] within the enclosing square brackets. PCRE also supports -this notation. For example, -
- [01[:alpha:]%] --matches "0", "1", any alphabetic character, or "%". The supported class names -are: -
- alnum letters and digits - alpha letters - ascii character codes 0 - 127 - blank space or tab only - cntrl control characters - digit decimal digits (same as \d) - graph printing characters, excluding space - lower lower case letters - print printing characters, including space - punct printing characters, excluding letters and digits and space - space white space (the same as \s from PCRE 8.34) - upper upper case letters - word "word" characters (same as \w) - xdigit hexadecimal digits --The default "space" characters are HT (9), LF (10), VT (11), FF (12), CR (13), -and space (32). If locale-specific matching is taking place, the list of space -characters may be different; there may be fewer or more of them. "Space" used -to be different to \s, which did not include VT, for Perl compatibility. -However, Perl changed at release 5.18, and PCRE followed at release 8.34. -"Space" and \s now match the same set of characters. - -
-The name "word" is a Perl extension, and "blank" is a GNU extension from Perl -5.8. Another Perl extension is negation, which is indicated by a ^ character -after the colon. For example, -
- [12[:^digit:]] --matches "1", "2", or any non-digit. PCRE (and Perl) also recognize the POSIX -syntax [.ch.] and [=ch=] where "ch" is a "collating element", but these are not -supported, and an error is given if they are encountered. - -
-By default, characters with values greater than 128 do not match any of the -POSIX character classes. However, if the PCRE_UCP option is passed to -pcre_compile(), some of the classes are changed so that Unicode character -properties are used. This is achieved by replacing certain POSIX classes by -other sequences, as follows: -
- [:alnum:] becomes \p{Xan} - [:alpha:] becomes \p{L} - [:blank:] becomes \h - [:digit:] becomes \p{Nd} - [:lower:] becomes \p{Ll} - [:space:] becomes \p{Xps} - [:upper:] becomes \p{Lu} - [:word:] becomes \p{Xwd} --Negated versions, such as [:^alpha:] use \P instead of \p. Three other POSIX -classes are handled specially in UCP mode: - -
-[:graph:] -This matches characters that have glyphs that mark the page when printed. In -Unicode property terms, it matches all characters with the L, M, N, P, S, or Cf -properties, except for: -
- U+061C Arabic Letter Mark - U+180E Mongolian Vowel Separator - U+2066 - U+2069 Various "isolate"s - -- -
-[:print:] -This matches the same characters as [:graph:] plus space characters that are -not controls, that is, characters with the Zs property. -
--[:punct:] -This matches all characters that have the Unicode P (punctuation) property, -plus those characters whose code points are less than 128 that have the S -(Symbol) property. -
--The other POSIX classes are unchanged, and match only characters with code -points less than 128. -
--In the POSIX.2 compliant library that was included in 4.4BSD Unix, the ugly -syntax [[:<:]] and [[:>:]] is used for matching "start of word" and "end of -word". PCRE treats these items as follows: -
- [[:<:]] is converted to \b(?=\w) - [[:>:]] is converted to \b(?<=\w) --Only these exact character sequences are recognized. A sequence such as -[a[:<:]b] provokes error for an unrecognized POSIX class name. This support is -not compatible with Perl. It is provided to help migrations from other -environments, and is best not used in any new patterns. Note that \b matches -at the start and the end of a word (see -"Simple assertions" -above), and in a Perl-style pattern the preceding or following character -normally shows which is wanted, without the need for the assertions that are -used above in order to give exactly the POSIX behaviour. - -
-Vertical bar characters are used to separate alternative patterns. For example, -the pattern -
- gilbert|sullivan --matches either "gilbert" or "sullivan". Any number of alternatives may appear, -and an empty alternative is permitted (matching the empty string). The matching -process tries each alternative in turn, from left to right, and the first one -that succeeds is used. If the alternatives are within a subpattern -(defined below), -"succeeds" means matching the rest of the main pattern as well as the -alternative in the subpattern. - -
-The settings of the PCRE_CASELESS, PCRE_MULTILINE, PCRE_DOTALL, and -PCRE_EXTENDED options (which are Perl-compatible) can be changed from within -the pattern by a sequence of Perl option letters enclosed between "(?" and ")". -The option letters are -
- i for PCRE_CASELESS - m for PCRE_MULTILINE - s for PCRE_DOTALL - x for PCRE_EXTENDED --For example, (?im) sets caseless, multiline matching. It is also possible to -unset these options by preceding the letter with a hyphen, and a combined -setting and unsetting such as (?im-sx), which sets PCRE_CASELESS and -PCRE_MULTILINE while unsetting PCRE_DOTALL and PCRE_EXTENDED, is also -permitted. If a letter appears both before and after the hyphen, the option is -unset. - -
-The PCRE-specific options PCRE_DUPNAMES, PCRE_UNGREEDY, and PCRE_EXTRA can be -changed in the same way as the Perl-compatible options by using the characters -J, U and X respectively. -
--When one of these option changes occurs at top level (that is, not inside -subpattern parentheses), the change applies to the remainder of the pattern -that follows. An option change within a subpattern (see below for a description -of subpatterns) affects only that part of the subpattern that follows it, so -
- (a(?i)b)c --matches abc and aBc and no other strings (assuming PCRE_CASELESS is not used). -By this means, options can be made to have different settings in different -parts of the pattern. Any changes made in one alternative do carry on -into subsequent branches within the same subpattern. For example, -
- (a(?i)b|c) --matches "ab", "aB", "c", and "C", even though when matching "C" the first -branch is abandoned before the option setting. This is because the effects of -option settings happen at compile time. There would be some very weird -behaviour otherwise. - -
-Note: There are other PCRE-specific options that can be set by the -application when the compiling or matching functions are called. In some cases -the pattern can contain special leading sequences such as (*CRLF) to override -what the application has set or what has been defaulted. Details are given in -the section entitled -"Newline sequences" -above. There are also the (*UTF8), (*UTF16),(*UTF32), and (*UCP) leading -sequences that can be used to set UTF and Unicode property modes; they are -equivalent to setting the PCRE_UTF8, PCRE_UTF16, PCRE_UTF32 and the PCRE_UCP -options, respectively. The (*UTF) sequence is a generic version that can be -used with any of the libraries. However, the application can set the -PCRE_NEVER_UTF option, which locks out the use of the (*UTF) sequences. -
-
-Subpatterns are delimited by parentheses (round brackets), which can be nested.
-Turning part of a pattern into a subpattern does two things:
-
-
-1. It localizes a set of alternatives. For example, the pattern
-
- cat(aract|erpillar|) --matches "cataract", "caterpillar", or "cat". Without the parentheses, it would -match "cataract", "erpillar" or an empty string. -
-Opening parentheses are counted from left to right (starting from 1) to obtain -numbers for the capturing subpatterns. For example, if the string "the red -king" is matched against the pattern -
- the ((red|white) (king|queen)) --the captured substrings are "red king", "red", and "king", and are numbered 1, -2, and 3, respectively. - -
-The fact that plain parentheses fulfil two functions is not always helpful. -There are often times when a grouping subpattern is required without a -capturing requirement. If an opening parenthesis is followed by a question mark -and a colon, the subpattern does not do any capturing, and is not counted when -computing the number of any subsequent capturing subpatterns. For example, if -the string "the white queen" is matched against the pattern -
- the ((?:red|white) (king|queen)) --the captured substrings are "white queen" and "queen", and are numbered 1 and -2. The maximum number of capturing subpatterns is 65535. - -
-As a convenient shorthand, if any option settings are required at the start of -a non-capturing subpattern, the option letters may appear between the "?" and -the ":". Thus the two patterns -
- (?i:saturday|sunday) - (?:(?i)saturday|sunday) --match exactly the same set of strings. Because alternative branches are tried -from left to right, and options are not reset until the end of the subpattern -is reached, an option setting in one branch does affect subsequent branches, so -the above patterns match "SUNDAY" as well as "Saturday". - -
-Perl 5.10 introduced a feature whereby each alternative in a subpattern uses -the same numbers for its capturing parentheses. Such a subpattern starts with -(?| and is itself a non-capturing subpattern. For example, consider this -pattern: -
- (?|(Sat)ur|(Sun))day --Because the two alternatives are inside a (?| group, both sets of capturing -parentheses are numbered one. Thus, when the pattern matches, you can look -at captured substring number one, whichever alternative matched. This construct -is useful when you want to capture part, but not all, of one of a number of -alternatives. Inside a (?| group, parentheses are numbered as usual, but the -number is reset at the start of each branch. The numbers of any capturing -parentheses that follow the subpattern start after the highest number used in -any branch. The following example is taken from the Perl documentation. The -numbers underneath show in which buffer the captured content will be stored. -
- # before ---------------branch-reset----------- after - / ( a ) (?| x ( y ) z | (p (q) r) | (t) u (v) ) ( z ) /x - # 1 2 2 3 2 3 4 --A back reference to a numbered subpattern uses the most recent value that is -set for that number by any subpattern. The following pattern matches "abcabc" -or "defdef": -
- /(?|(abc)|(def))\1/ --In contrast, a subroutine call to a numbered subpattern always refers to the -first one in the pattern with the given number. The following pattern matches -"abcabc" or "defabc": -
- /(?|(abc)|(def))(?1)/ --If a -condition test -for a subpattern's having matched refers to a non-unique number, the test is -true if any of the subpatterns of that number have matched. - -
-An alternative approach to using this "branch reset" feature is to use -duplicate named subpatterns, as described in the next section. -
--Identifying capturing parentheses by number is simple, but it can be very hard -to keep track of the numbers in complicated regular expressions. Furthermore, -if an expression is modified, the numbers may change. To help with this -difficulty, PCRE supports the naming of subpatterns. This feature was not -added to Perl until release 5.10. Python had the feature earlier, and PCRE -introduced it at release 4.0, using the Python syntax. PCRE now supports both -the Perl and the Python syntax. Perl allows identically numbered subpatterns to -have different names, but PCRE does not. -
--In PCRE, a subpattern can be named in one of three ways: (?<name>...) or -(?'name'...) as in Perl, or (?P<name>...) as in Python. References to capturing -parentheses from other parts of the pattern, such as -back references, -recursion, -and -conditions, -can be made by name as well as by number. -
--Names consist of up to 32 alphanumeric characters and underscores, but must -start with a non-digit. Named capturing parentheses are still allocated numbers -as well as names, exactly as if the names were not present. The PCRE API -provides function calls for extracting the name-to-number translation table -from a compiled pattern. There is also a convenience function for extracting a -captured substring by name. -
--By default, a name must be unique within a pattern, but it is possible to relax -this constraint by setting the PCRE_DUPNAMES option at compile time. (Duplicate -names are also always permitted for subpatterns with the same number, set up as -described in the previous section.) Duplicate names can be useful for patterns -where only one instance of the named parentheses can match. Suppose you want to -match the name of a weekday, either as a 3-letter abbreviation or as the full -name, and in both cases you want to extract the abbreviation. This pattern -(ignoring the line breaks) does the job: -
- (?<DN>Mon|Fri|Sun)(?:day)?| - (?<DN>Tue)(?:sday)?| - (?<DN>Wed)(?:nesday)?| - (?<DN>Thu)(?:rsday)?| - (?<DN>Sat)(?:urday)? --There are five capturing substrings, but only one is ever set after a match. -(An alternative way of solving this problem is to use a "branch reset" -subpattern, as described in the previous section.) - -
-The convenience function for extracting the data by name returns the substring -for the first (and in this example, the only) subpattern of that name that -matched. This saves searching to find which numbered subpattern it was. -
--If you make a back reference to a non-unique named subpattern from elsewhere in -the pattern, the subpatterns to which the name refers are checked in the order -in which they appear in the overall pattern. The first one that is set is used -for the reference. For example, this pattern matches both "foofoo" and -"barbar" but not "foobar" or "barfoo": -
- (?:(?<n>foo)|(?<n>bar))\k<n> - -- -
-If you make a subroutine call to a non-unique named subpattern, the one that -corresponds to the first occurrence of the name is used. In the absence of -duplicate numbers (see the previous section) this is the one with the lowest -number. -
--If you use a named reference in a condition -test (see the -section about conditions -below), either to check whether a subpattern has matched, or to check for -recursion, all subpatterns with the same name are tested. If the condition is -true for any one of them, the overall condition is true. This is the same -behaviour as testing by number. For further details of the interfaces for -handling named subpatterns, see the -pcreapi -documentation. -
--Warning: You cannot use different names to distinguish between two -subpatterns with the same number because PCRE uses only the numbers when -matching. For this reason, an error is given at compile time if different names -are given to subpatterns with the same number. However, you can always give the -same name to subpatterns with the same number, even when PCRE_DUPNAMES is not -set. -
--Repetition is specified by quantifiers, which can follow any of the following -items: -
- a literal data character - the dot metacharacter - the \C escape sequence - the \X escape sequence - the \R escape sequence - an escape such as \d or \pL that matches a single character - a character class - a back reference (see next section) - a parenthesized subpattern (including assertions) - a subroutine call to a subpattern (recursive or otherwise) --The general repetition quantifier specifies a minimum and maximum number of -permitted matches, by giving the two numbers in curly brackets (braces), -separated by a comma. The numbers must be less than 65536, and the first must -be less than or equal to the second. For example: -
- z{2,4} --matches "zz", "zzz", or "zzzz". A closing brace on its own is not a special -character. If the second number is omitted, but the comma is present, there is -no upper limit; if the second number and the comma are both omitted, the -quantifier specifies an exact number of required matches. Thus -
- [aeiou]{3,} --matches at least 3 successive vowels, but may match many more, while -
- \d{8} --matches exactly 8 digits. An opening curly bracket that appears in a position -where a quantifier is not allowed, or one that does not match the syntax of a -quantifier, is taken as a literal character. For example, {,6} is not a -quantifier, but a literal string of four characters. - -
-In UTF modes, quantifiers apply to characters rather than to individual data -units. Thus, for example, \x{100}{2} matches two characters, each of -which is represented by a two-byte sequence in a UTF-8 string. Similarly, -\X{3} matches three Unicode extended grapheme clusters, each of which may be -several data units long (and they may be of different lengths). -
--The quantifier {0} is permitted, causing the expression to behave as if the -previous item and the quantifier were not present. This may be useful for -subpatterns that are referenced as -subroutines -from elsewhere in the pattern (but see also the section entitled -"Defining subpatterns for use by reference only" -below). Items other than subpatterns that have a {0} quantifier are omitted -from the compiled pattern. -
--For convenience, the three most common quantifiers have single-character -abbreviations: -
- * is equivalent to {0,} - + is equivalent to {1,} - ? is equivalent to {0,1} --It is possible to construct infinite loops by following a subpattern that can -match no characters with a quantifier that has no upper limit, for example: -
- (a?)* --Earlier versions of Perl and PCRE used to give an error at compile time for -such patterns. However, because there are cases where this can be useful, such -patterns are now accepted, but if any repetition of the subpattern does in fact -match no characters, the loop is forcibly broken. - -
-By default, the quantifiers are "greedy", that is, they match as much as -possible (up to the maximum number of permitted times), without causing the -rest of the pattern to fail. The classic example of where this gives problems -is in trying to match comments in C programs. These appear between /* and */ -and within the comment, individual * and / characters may appear. An attempt to -match C comments by applying the pattern -
- /\*.*\*/ --to the string -
- /* first comment */ not comment /* second comment */ --fails, because it matches the entire string owing to the greediness of the .* -item. - -
-However, if a quantifier is followed by a question mark, it ceases to be -greedy, and instead matches the minimum number of times possible, so the -pattern -
- /\*.*?\*/ --does the right thing with the C comments. The meaning of the various -quantifiers is not otherwise changed, just the preferred number of matches. -Do not confuse this use of question mark with its use as a quantifier in its -own right. Because it has two uses, it can sometimes appear doubled, as in -
- \d??\d --which matches one digit by preference, but can match two if that is the only -way the rest of the pattern matches. - -
-If the PCRE_UNGREEDY option is set (an option that is not available in Perl), -the quantifiers are not greedy by default, but individual ones can be made -greedy by following them with a question mark. In other words, it inverts the -default behaviour. -
--When a parenthesized subpattern is quantified with a minimum repeat count that -is greater than 1 or with a limited maximum, more memory is required for the -compiled pattern, in proportion to the size of the minimum or maximum. -
--If a pattern starts with .* or .{0,} and the PCRE_DOTALL option (equivalent -to Perl's /s) is set, thus allowing the dot to match newlines, the pattern is -implicitly anchored, because whatever follows will be tried against every -character position in the subject string, so there is no point in retrying the -overall match at any position after the first. PCRE normally treats such a -pattern as though it were preceded by \A. -
--In cases where it is known that the subject string contains no newlines, it is -worth setting PCRE_DOTALL in order to obtain this optimization, or -alternatively using ^ to indicate anchoring explicitly. -
--However, there are some cases where the optimization cannot be used. When .* -is inside capturing parentheses that are the subject of a back reference -elsewhere in the pattern, a match at the start may fail where a later one -succeeds. Consider, for example: -
- (.*)abc\1 --If the subject is "xyz123abc123" the match point is the fourth character. For -this reason, such a pattern is not implicitly anchored. - -
-Another case where implicit anchoring is not applied is when the leading .* is -inside an atomic group. Once again, a match at the start may fail where a later -one succeeds. Consider this pattern: -
- (?>.*?a)b --It matches "ab" in the subject "aab". The use of the backtracking control verbs -(*PRUNE) and (*SKIP) also disable this optimization. - -
-When a capturing subpattern is repeated, the value captured is the substring -that matched the final iteration. For example, after -
- (tweedle[dume]{3}\s*)+ --has matched "tweedledum tweedledee" the value of the captured substring is -"tweedledee". However, if there are nested capturing subpatterns, the -corresponding captured values may have been set in previous iterations. For -example, after -
- /(a|(b))+/ --matches "aba" the value of the second captured substring is "b". - -
-With both maximizing ("greedy") and minimizing ("ungreedy" or "lazy") -repetition, failure of what follows normally causes the repeated item to be -re-evaluated to see if a different number of repeats allows the rest of the -pattern to match. Sometimes it is useful to prevent this, either to change the -nature of the match, or to cause it fail earlier than it otherwise might, when -the author of the pattern knows there is no point in carrying on. -
--Consider, for example, the pattern \d+foo when applied to the subject line -
- 123456bar --After matching all 6 digits and then failing to match "foo", the normal -action of the matcher is to try again with only 5 digits matching the \d+ -item, and then with 4, and so on, before ultimately failing. "Atomic grouping" -(a term taken from Jeffrey Friedl's book) provides the means for specifying -that once a subpattern has matched, it is not to be re-evaluated in this way. - -
-If we use atomic grouping for the previous example, the matcher gives up -immediately on failing to match "foo" the first time. The notation is a kind of -special parenthesis, starting with (?> as in this example: -
- (?>\d+)foo --This kind of parenthesis "locks up" the part of the pattern it contains once -it has matched, and a failure further into the pattern is prevented from -backtracking into it. Backtracking past it to previous items, however, works as -normal. - -
-An alternative description is that a subpattern of this type matches the string -of characters that an identical standalone pattern would match, if anchored at -the current point in the subject string. -
--Atomic grouping subpatterns are not capturing subpatterns. Simple cases such as -the above example can be thought of as a maximizing repeat that must swallow -everything it can. So, while both \d+ and \d+? are prepared to adjust the -number of digits they match in order to make the rest of the pattern match, -(?>\d+) can only match an entire sequence of digits. -
--Atomic groups in general can of course contain arbitrarily complicated -subpatterns, and can be nested. However, when the subpattern for an atomic -group is just a single repeated item, as in the example above, a simpler -notation, called a "possessive quantifier" can be used. This consists of an -additional + character following a quantifier. Using this notation, the -previous example can be rewritten as -
- \d++foo --Note that a possessive quantifier can be used with an entire group, for -example: -
- (abc|xyz){2,3}+ --Possessive quantifiers are always greedy; the setting of the PCRE_UNGREEDY -option is ignored. They are a convenient notation for the simpler forms of -atomic group. However, there is no difference in the meaning of a possessive -quantifier and the equivalent atomic group, though there may be a performance -difference; possessive quantifiers should be slightly faster. - -
-The possessive quantifier syntax is an extension to the Perl 5.8 syntax. -Jeffrey Friedl originated the idea (and the name) in the first edition of his -book. Mike McCloskey liked it, so implemented it when he built Sun's Java -package, and PCRE copied it from there. It ultimately found its way into Perl -at release 5.10. -
--PCRE has an optimization that automatically "possessifies" certain simple -pattern constructs. For example, the sequence A+B is treated as A++B because -there is no point in backtracking into a sequence of A's when B must follow. -
--When a pattern contains an unlimited repeat inside a subpattern that can itself -be repeated an unlimited number of times, the use of an atomic group is the -only way to avoid some failing matches taking a very long time indeed. The -pattern -
- (\D+|<\d+>)*[!?] --matches an unlimited number of substrings that either consist of non-digits, or -digits enclosed in <>, followed by either ! or ?. When it matches, it runs -quickly. However, if it is applied to -
- aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa --it takes a long time before reporting failure. This is because the string can -be divided between the internal \D+ repeat and the external * repeat in a -large number of ways, and all have to be tried. (The example uses [!?] rather -than a single character at the end, because both PCRE and Perl have an -optimization that allows for fast failure when a single character is used. They -remember the last single character that is required for a match, and fail early -if it is not present in the string.) If the pattern is changed so that it uses -an atomic group, like this: -
- ((?>\D+)|<\d+>)*[!?] --sequences of non-digits cannot be broken, and failure happens quickly. - -
-Outside a character class, a backslash followed by a digit greater than 0 (and -possibly further digits) is a back reference to a capturing subpattern earlier -(that is, to its left) in the pattern, provided there have been that many -previous capturing left parentheses. -
--However, if the decimal number following the backslash is less than 10, it is -always taken as a back reference, and causes an error only if there are not -that many capturing left parentheses in the entire pattern. In other words, the -parentheses that are referenced need not be to the left of the reference for -numbers less than 10. A "forward back reference" of this type can make sense -when a repetition is involved and the subpattern to the right has participated -in an earlier iteration. -
--It is not possible to have a numerical "forward back reference" to a subpattern -whose number is 10 or more using this syntax because a sequence such as \50 is -interpreted as a character defined in octal. See the subsection entitled -"Non-printing characters" -above -for further details of the handling of digits following a backslash. There is -no such problem when named parentheses are used. A back reference to any -subpattern is possible using named parentheses (see below). -
--Another way of avoiding the ambiguity inherent in the use of digits following a -backslash is to use the \g escape sequence. This escape must be followed by an -unsigned number or a negative number, optionally enclosed in braces. These -examples are all identical: -
- (ring), \1 - (ring), \g1 - (ring), \g{1} --An unsigned number specifies an absolute reference without the ambiguity that -is present in the older syntax. It is also useful when literal digits follow -the reference. A negative number is a relative reference. Consider this -example: -
- (abc(def)ghi)\g{-1} --The sequence \g{-1} is a reference to the most recently started capturing -subpattern before \g, that is, is it equivalent to \2 in this example. -Similarly, \g{-2} would be equivalent to \1. The use of relative references -can be helpful in long patterns, and also in patterns that are created by -joining together fragments that contain references within themselves. - -
-A back reference matches whatever actually matched the capturing subpattern in -the current subject string, rather than anything matching the subpattern -itself (see -"Subpatterns as subroutines" -below for a way of doing that). So the pattern -
- (sens|respons)e and \1ibility --matches "sense and sensibility" and "response and responsibility", but not -"sense and responsibility". If caseful matching is in force at the time of the -back reference, the case of letters is relevant. For example, -
- ((?i)rah)\s+\1 --matches "rah rah" and "RAH RAH", but not "RAH rah", even though the original -capturing subpattern is matched caselessly. - -
-There are several different ways of writing back references to named -subpatterns. The .NET syntax \k{name} and the Perl syntax \k<name> or -\k'name' are supported, as is the Python syntax (?P=name). Perl 5.10's unified -back reference syntax, in which \g can be used for both numeric and named -references, is also supported. We could rewrite the above example in any of -the following ways: -
- (?<p1>(?i)rah)\s+\k<p1> - (?'p1'(?i)rah)\s+\k{p1} - (?P<p1>(?i)rah)\s+(?P=p1) - (?<p1>(?i)rah)\s+\g{p1} --A subpattern that is referenced by name may appear in the pattern before or -after the reference. - -
-There may be more than one back reference to the same subpattern. If a -subpattern has not actually been used in a particular match, any back -references to it always fail by default. For example, the pattern -
- (a|(bc))\2 --always fails if it starts to match "a" rather than "bc". However, if the -PCRE_JAVASCRIPT_COMPAT option is set at compile time, a back reference to an -unset value matches an empty string. - -
-Because there may be many capturing parentheses in a pattern, all digits -following a backslash are taken as part of a potential back reference number. -If the pattern continues with a digit character, some delimiter must be used to -terminate the back reference. If the PCRE_EXTENDED option is set, this can be -white space. Otherwise, the \g{ syntax or an empty comment (see -"Comments" -below) can be used. -
--A back reference that occurs inside the parentheses to which it refers fails -when the subpattern is first used, so, for example, (a\1) never matches. -However, such references can be useful inside repeated subpatterns. For -example, the pattern -
- (a|b\1)+ --matches any number of "a"s and also "aba", "ababbaa" etc. At each iteration of -the subpattern, the back reference matches the character string corresponding -to the previous iteration. In order for this to work, the pattern must be such -that the first iteration does not need to match the back reference. This can be -done using alternation, as in the example above, or by a quantifier with a -minimum of zero. - -
-Back references of this type cause the group that they reference to be treated -as an -atomic group. -Once the whole group has been matched, a subsequent matching failure cannot -cause backtracking into the middle of the group. -
--An assertion is a test on the characters following or preceding the current -matching point that does not actually consume any characters. The simple -assertions coded as \b, \B, \A, \G, \Z, \z, ^ and $ are described -above. -
--More complicated assertions are coded as subpatterns. There are two kinds: -those that look ahead of the current position in the subject string, and those -that look behind it. An assertion subpattern is matched in the normal way, -except that it does not cause the current matching position to be changed. -
--Assertion subpatterns are not capturing subpatterns. If such an assertion -contains capturing subpatterns within it, these are counted for the purposes of -numbering the capturing subpatterns in the whole pattern. However, substring -capturing is carried out only for positive assertions. (Perl sometimes, but not -always, does do capturing in negative assertions.) -
--WARNING: If a positive assertion containing one or more capturing subpatterns -succeeds, but failure to match later in the pattern causes backtracking over -this assertion, the captures within the assertion are reset only if no higher -numbered captures are already set. This is, unfortunately, a fundamental -limitation of the current implementation, and as PCRE1 is now in -maintenance-only status, it is unlikely ever to change. -
-
-For compatibility with Perl, assertion subpatterns may be repeated; though
-it makes no sense to assert the same thing several times, the side effect of
-capturing parentheses may occasionally be useful. In practice, there only three
-cases:
-
-
-(1) If the quantifier is {0}, the assertion is never obeyed during matching.
-However, it may contain internal capturing parenthesized groups that are called
-from elsewhere via the
-subroutine mechanism.
-
-
-(2) If quantifier is {0,n} where n is greater than zero, it is treated as if it
-were {0,1}. At run time, the rest of the pattern match is tried with and
-without the assertion, the order depending on the greediness of the quantifier.
-
-
-(3) If the minimum repetition is greater than zero, the quantifier is ignored.
-The assertion is obeyed just once when encountered during matching.
-
-Lookahead assertions start with (?= for positive assertions and (?! for -negative assertions. For example, -
- \w+(?=;) --matches a word followed by a semicolon, but does not include the semicolon in -the match, and -
- foo(?!bar) --matches any occurrence of "foo" that is not followed by "bar". Note that the -apparently similar pattern -
- (?!foo)bar --does not find an occurrence of "bar" that is preceded by something other than -"foo"; it finds any occurrence of "bar" whatsoever, because the assertion -(?!foo) is always true when the next three characters are "bar". A -lookbehind assertion is needed to achieve the other effect. - -
-If you want to force a matching failure at some point in a pattern, the most -convenient way to do it is with (?!) because an empty string always matches, so -an assertion that requires there not to be an empty string must always fail. -The backtracking control verb (*FAIL) or (*F) is a synonym for (?!). -
--Lookbehind assertions start with (?<= for positive assertions and (?<! for -negative assertions. For example, -
- (?<!foo)bar --does find an occurrence of "bar" that is not preceded by "foo". The contents of -a lookbehind assertion are restricted such that all the strings it matches must -have a fixed length. However, if there are several top-level alternatives, they -do not all have to have the same fixed length. Thus -
- (?<=bullock|donkey) --is permitted, but -
- (?<!dogs?|cats?) --causes an error at compile time. Branches that match different length strings -are permitted only at the top level of a lookbehind assertion. This is an -extension compared with Perl, which requires all branches to match the same -length of string. An assertion such as -
- (?<=ab(c|de)) --is not permitted, because its single top-level branch can match two different -lengths, but it is acceptable to PCRE if rewritten to use two top-level -branches: -
- (?<=abc|abde) --In some cases, the escape sequence \K -(see above) -can be used instead of a lookbehind assertion to get round the fixed-length -restriction. - -
-The implementation of lookbehind assertions is, for each alternative, to -temporarily move the current position back by the fixed length and then try to -match. If there are insufficient characters before the current position, the -assertion fails. -
--In a UTF mode, PCRE does not allow the \C escape (which matches a single data -unit even in a UTF mode) to appear in lookbehind assertions, because it makes -it impossible to calculate the length of the lookbehind. The \X and \R -escapes, which can match different numbers of data units, are also not -permitted. -
--"Subroutine" -calls (see below) such as (?2) or (?&X) are permitted in lookbehinds, as long -as the subpattern matches a fixed-length string. -Recursion, -however, is not supported. -
--Possessive quantifiers can be used in conjunction with lookbehind assertions to -specify efficient matching of fixed-length strings at the end of subject -strings. Consider a simple pattern such as -
- abcd$ --when applied to a long string that does not match. Because matching proceeds -from left to right, PCRE will look for each "a" in the subject and then see if -what follows matches the rest of the pattern. If the pattern is specified as -
- ^.*abcd$ --the initial .* matches the entire string at first, but when this fails (because -there is no following "a"), it backtracks to match all but the last character, -then all but the last two characters, and so on. Once again the search for "a" -covers the entire string, from right to left, so we are no better off. However, -if the pattern is written as -
- ^.*+(?<=abcd) --there can be no backtracking for the .*+ item; it can match only the entire -string. The subsequent lookbehind assertion does a single test on the last four -characters. If it fails, the match fails immediately. For long strings, this -approach makes a significant difference to the processing time. - -
-Several assertions (of any sort) may occur in succession. For example, -
- (?<=\d{3})(?<!999)foo --matches "foo" preceded by three digits that are not "999". Notice that each of -the assertions is applied independently at the same point in the subject -string. First there is a check that the previous three characters are all -digits, and then there is a check that the same three characters are not "999". -This pattern does not match "foo" preceded by six characters, the first -of which are digits and the last three of which are not "999". For example, it -doesn't match "123abcfoo". A pattern to do that is -
- (?<=\d{3}...)(?<!999)foo --This time the first assertion looks at the preceding six characters, checking -that the first three are digits, and then the second assertion checks that the -preceding three characters are not "999". - -
-Assertions can be nested in any combination. For example, -
- (?<=(?<!foo)bar)baz --matches an occurrence of "baz" that is preceded by "bar" which in turn is not -preceded by "foo", while -
- (?<=\d{3}(?!999)...)foo --is another pattern that matches "foo" preceded by three digits and any three -characters that are not "999". - -
-It is possible to cause the matching process to obey a subpattern -conditionally or to choose between two alternative subpatterns, depending on -the result of an assertion, or whether a specific capturing subpattern has -already been matched. The two possible forms of conditional subpattern are: -
- (?(condition)yes-pattern) - (?(condition)yes-pattern|no-pattern) --If the condition is satisfied, the yes-pattern is used; otherwise the -no-pattern (if present) is used. If there are more than two alternatives in the -subpattern, a compile-time error occurs. Each of the two alternatives may -itself contain nested subpatterns of any form, including conditional -subpatterns; the restriction to two alternatives applies only at the level of -the condition. This pattern fragment is an example where the alternatives are -complex: -
- (?(1) (A|B|C) | (D | (?(2)E|F) | E) ) - -- -
-There are four kinds of condition: references to subpatterns, references to -recursion, a pseudo-condition called DEFINE, and assertions. -
--If the text between the parentheses consists of a sequence of digits, the -condition is true if a capturing subpattern of that number has previously -matched. If there is more than one capturing subpattern with the same number -(see the earlier -section about duplicate subpattern numbers), -the condition is true if any of them have matched. An alternative notation is -to precede the digits with a plus or minus sign. In this case, the subpattern -number is relative rather than absolute. The most recently opened parentheses -can be referenced by (?(-1), the next most recent by (?(-2), and so on. Inside -loops it can also make sense to refer to subsequent groups. The next -parentheses to be opened can be referenced as (?(+1), and so on. (The value -zero in any of these forms is not used; it provokes a compile-time error.) -
--Consider the following pattern, which contains non-significant white space to -make it more readable (assume the PCRE_EXTENDED option) and to divide it into -three parts for ease of discussion: -
- ( \( )? [^()]+ (?(1) \) ) --The first part matches an optional opening parenthesis, and if that -character is present, sets it as the first captured substring. The second part -matches one or more characters that are not parentheses. The third part is a -conditional subpattern that tests whether or not the first set of parentheses -matched. If they did, that is, if subject started with an opening parenthesis, -the condition is true, and so the yes-pattern is executed and a closing -parenthesis is required. Otherwise, since no-pattern is not present, the -subpattern matches nothing. In other words, this pattern matches a sequence of -non-parentheses, optionally enclosed in parentheses. - -
-If you were embedding this pattern in a larger one, you could use a relative -reference: -
- ...other stuff... ( \( )? [^()]+ (?(-1) \) ) ... --This makes the fragment independent of the parentheses in the larger pattern. - -
-Perl uses the syntax (?(<name>)...) or (?('name')...) to test for a used -subpattern by name. For compatibility with earlier versions of PCRE, which had -this facility before Perl, the syntax (?(name)...) is also recognized. -
--Rewriting the above example to use a named subpattern gives this: -
- (?<OPEN> \( )? [^()]+ (?(<OPEN>) \) ) --If the name used in a condition of this kind is a duplicate, the test is -applied to all subpatterns of the same name, and is true if any one of them has -matched. - -
-If the condition is the string (R), and there is no subpattern with the name R, -the condition is true if a recursive call to the whole pattern or any -subpattern has been made. If digits or a name preceded by ampersand follow the -letter R, for example: -
- (?(R3)...) or (?(R&name)...) --the condition is true if the most recent recursion is into a subpattern whose -number or name is given. This condition does not check the entire recursion -stack. If the name used in a condition of this kind is a duplicate, the test is -applied to all subpatterns of the same name, and is true if any one of them is -the most recent recursion. - -
-At "top level", all these recursion test conditions are false. -The syntax for recursive patterns -is described below. -
--If the condition is the string (DEFINE), and there is no subpattern with the -name DEFINE, the condition is always false. In this case, there may be only one -alternative in the subpattern. It is always skipped if control reaches this -point in the pattern; the idea of DEFINE is that it can be used to define -subroutines that can be referenced from elsewhere. (The use of -subroutines -is described below.) For example, a pattern to match an IPv4 address such as -"192.168.23.245" could be written like this (ignore white space and line -breaks): -
- (?(DEFINE) (?<byte> 2[0-4]\d | 25[0-5] | 1\d\d | [1-9]?\d) ) - \b (?&byte) (\.(?&byte)){3} \b --The first part of the pattern is a DEFINE group inside which a another group -named "byte" is defined. This matches an individual component of an IPv4 -address (a number less than 256). When matching takes place, this part of the -pattern is skipped because DEFINE acts like a false condition. The rest of the -pattern uses references to the named group to match the four dot-separated -components of an IPv4 address, insisting on a word boundary at each end. - -
-If the condition is not in any of the above formats, it must be an assertion. -This may be a positive or negative lookahead or lookbehind assertion. Consider -this pattern, again containing non-significant white space, and with the two -alternatives on the second line: -
- (?(?=[^a-z]*[a-z]) - \d{2}-[a-z]{3}-\d{2} | \d{2}-\d{2}-\d{2} ) --The condition is a positive lookahead assertion that matches an optional -sequence of non-letters followed by a letter. In other words, it tests for the -presence of at least one letter in the subject. If a letter is found, the -subject is matched against the first alternative; otherwise it is matched -against the second. This pattern matches strings in one of the two forms -dd-aaa-dd or dd-dd-dd, where aaa are letters and dd are digits. - -
-There are two ways of including comments in patterns that are processed by -PCRE. In both cases, the start of the comment must not be in a character class, -nor in the middle of any other sequence of related characters such as (?: or a -subpattern name or number. The characters that make up a comment play no part -in the pattern matching. -
--The sequence (?# marks the start of a comment that continues up to the next -closing parenthesis. Nested parentheses are not permitted. If the PCRE_EXTENDED -option is set, an unescaped # character also introduces a comment, which in -this case continues to immediately after the next newline character or -character sequence in the pattern. Which characters are interpreted as newlines -is controlled by the options passed to a compiling function or by a special -sequence at the start of the pattern, as described in the section entitled -"Newline conventions" -above. Note that the end of this type of comment is a literal newline sequence -in the pattern; escape sequences that happen to represent a newline do not -count. For example, consider this pattern when PCRE_EXTENDED is set, and the -default newline convention is in force: -
- abc #comment \n still comment --On encountering the # character, pcre_compile() skips along, looking for -a newline in the pattern. The sequence \n is still literal at this stage, so -it does not terminate the comment. Only an actual character with the code value -0x0a (the default newline) does so. - -
-Consider the problem of matching a string in parentheses, allowing for -unlimited nested parentheses. Without the use of recursion, the best that can -be done is to use a pattern that matches up to some fixed depth of nesting. It -is not possible to handle an arbitrary nesting depth. -
--For some time, Perl has provided a facility that allows regular expressions to -recurse (amongst other things). It does this by interpolating Perl code in the -expression at run time, and the code can refer to the expression itself. A Perl -pattern using code interpolation to solve the parentheses problem can be -created like this: -
- $re = qr{\( (?: (?>[^()]+) | (?p{$re}) )* \)}x; --The (?p{...}) item interpolates Perl code at run time, and in this case refers -recursively to the pattern in which it appears. - -
-Obviously, PCRE cannot support the interpolation of Perl code. Instead, it -supports special syntax for recursion of the entire pattern, and also for -individual subpattern recursion. After its introduction in PCRE and Python, -this kind of recursion was subsequently introduced into Perl at release 5.10. -
--A special item that consists of (? followed by a number greater than zero and a -closing parenthesis is a recursive subroutine call of the subpattern of the -given number, provided that it occurs inside that subpattern. (If not, it is a -non-recursive subroutine -call, which is described in the next section.) The special item (?R) or (?0) is -a recursive call of the entire regular expression. -
--This PCRE pattern solves the nested parentheses problem (assume the -PCRE_EXTENDED option is set so that white space is ignored): -
- \( ( [^()]++ | (?R) )* \) --First it matches an opening parenthesis. Then it matches any number of -substrings which can either be a sequence of non-parentheses, or a recursive -match of the pattern itself (that is, a correctly parenthesized substring). -Finally there is a closing parenthesis. Note the use of a possessive quantifier -to avoid backtracking into sequences of non-parentheses. - -
-If this were part of a larger pattern, you would not want to recurse the entire -pattern, so instead you could use this: -
- ( \( ( [^()]++ | (?1) )* \) ) --We have put the pattern into parentheses, and caused the recursion to refer to -them instead of the whole pattern. - -
-In a larger pattern, keeping track of parenthesis numbers can be tricky. This -is made easier by the use of relative references. Instead of (?1) in the -pattern above you can write (?-2) to refer to the second most recently opened -parentheses preceding the recursion. In other words, a negative number counts -capturing parentheses leftwards from the point at which it is encountered. -
--It is also possible to refer to subsequently opened parentheses, by writing -references such as (?+2). However, these cannot be recursive because the -reference is not inside the parentheses that are referenced. They are always -non-recursive subroutine -calls, as described in the next section. -
--An alternative approach is to use named parentheses instead. The Perl syntax -for this is (?&name); PCRE's earlier syntax (?P>name) is also supported. We -could rewrite the above example as follows: -
- (?<pn> \( ( [^()]++ | (?&pn) )* \) ) --If there is more than one subpattern with the same name, the earliest one is -used. - -
-This particular example pattern that we have been looking at contains nested -unlimited repeats, and so the use of a possessive quantifier for matching -strings of non-parentheses is important when applying the pattern to strings -that do not match. For example, when this pattern is applied to -
- (aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa() --it yields "no match" quickly. However, if a possessive quantifier is not used, -the match runs for a very long time indeed because there are so many different -ways the + and * repeats can carve up the subject, and all have to be tested -before failure can be reported. - -
-At the end of a match, the values of capturing parentheses are those from -the outermost level. If you want to obtain intermediate values, a callout -function can be used (see below and the -pcrecallout -documentation). If the pattern above is matched against -
- (ab(cd)ef) --the value for the inner capturing parentheses (numbered 2) is "ef", which is -the last value taken on at the top level. If a capturing subpattern is not -matched at the top level, its final captured value is unset, even if it was -(temporarily) set at a deeper level during the matching process. - -
-If there are more than 15 capturing parentheses in a pattern, PCRE has to -obtain extra memory to store data during a recursion, which it does by using -pcre_malloc, freeing it via pcre_free afterwards. If no memory can -be obtained, the match fails with the PCRE_ERROR_NOMEMORY error. -
--Do not confuse the (?R) item with the condition (R), which tests for recursion. -Consider this pattern, which matches text in angle brackets, allowing for -arbitrary nesting. Only digits are allowed in nested brackets (that is, when -recursing), whereas any characters are permitted at the outer level. -
- < (?: (?(R) \d++ | [^<>]*+) | (?R)) * > --In this pattern, (?(R) is the start of a conditional subpattern, with two -different alternatives for the recursive and non-recursive cases. The (?R) item -is the actual recursive call. - -
-Recursion processing in PCRE differs from Perl in two important ways. In PCRE -(like Python, but unlike Perl), a recursive subpattern call is always treated -as an atomic group. That is, once it has matched some of the subject string, it -is never re-entered, even if it contains untried alternatives and there is a -subsequent matching failure. This can be illustrated by the following pattern, -which purports to match a palindromic string that contains an odd number of -characters (for example, "a", "aba", "abcba", "abcdcba"): -
- ^(.|(.)(?1)\2)$ --The idea is that it either matches a single character, or two identical -characters surrounding a sub-palindrome. In Perl, this pattern works; in PCRE -it does not if the pattern is longer than three characters. Consider the -subject string "abcba": - -
-At the top level, the first character is matched, but as it is not at the end -of the string, the first alternative fails; the second alternative is taken -and the recursion kicks in. The recursive call to subpattern 1 successfully -matches the next character ("b"). (Note that the beginning and end of line -tests are not part of the recursion). -
--Back at the top level, the next character ("c") is compared with what -subpattern 2 matched, which was "a". This fails. Because the recursion is -treated as an atomic group, there are now no backtracking points, and so the -entire match fails. (Perl is able, at this point, to re-enter the recursion and -try the second alternative.) However, if the pattern is written with the -alternatives in the other order, things are different: -
- ^((.)(?1)\2|.)$ --This time, the recursing alternative is tried first, and continues to recurse -until it runs out of characters, at which point the recursion fails. But this -time we do have another alternative to try at the higher level. That is the big -difference: in the previous case the remaining alternative is at a deeper -recursion level, which PCRE cannot use. - -
-To change the pattern so that it matches all palindromic strings, not just -those with an odd number of characters, it is tempting to change the pattern to -this: -
- ^((.)(?1)\2|.?)$ --Again, this works in Perl, but not in PCRE, and for the same reason. When a -deeper recursion has matched a single character, it cannot be entered again in -order to match an empty string. The solution is to separate the two cases, and -write out the odd and even cases as alternatives at the higher level: -
- ^(?:((.)(?1)\2|)|((.)(?3)\4|.)) --If you want to match typical palindromic phrases, the pattern has to ignore all -non-word characters, which can be done like this: -
- ^\W*+(?:((.)\W*+(?1)\W*+\2|)|((.)\W*+(?3)\W*+\4|\W*+.\W*+))\W*+$ --If run with the PCRE_CASELESS option, this pattern matches phrases such as "A -man, a plan, a canal: Panama!" and it works well in both PCRE and Perl. Note -the use of the possessive quantifier *+ to avoid backtracking into sequences of -non-word characters. Without this, PCRE takes a great deal longer (ten times or -more) to match typical phrases, and Perl takes so long that you think it has -gone into a loop. - -
-WARNING: The palindrome-matching patterns above work only if the subject -string does not start with a palindrome that is shorter than the entire string. -For example, although "abcba" is correctly matched, if the subject is "ababa", -PCRE finds the palindrome "aba" at the start, then fails at top level because -the end of the string does not follow. Once again, it cannot jump back into the -recursion to try other alternatives, so the entire match fails. -
--The second way in which PCRE and Perl differ in their recursion processing is -in the handling of captured values. In Perl, when a subpattern is called -recursively or as a subpattern (see the next section), it has no access to any -values that were captured outside the recursion, whereas in PCRE these values -can be referenced. Consider this pattern: -
- ^(.)(\1|a(?2)) --In PCRE, this pattern matches "bab". The first capturing parentheses match "b", -then in the second group, when the back reference \1 fails to match "b", the -second alternative matches "a" and then recurses. In the recursion, \1 does -now match "b" and so the whole match succeeds. In Perl, the pattern fails to -match because inside the recursive call \1 cannot access the externally set -value. - -
-If the syntax for a recursive subpattern call (either by number or by -name) is used outside the parentheses to which it refers, it operates like a -subroutine in a programming language. The called subpattern may be defined -before or after the reference. A numbered reference can be absolute or -relative, as in these examples: -
- (...(absolute)...)...(?2)... - (...(relative)...)...(?-1)... - (...(?+1)...(relative)... --An earlier example pointed out that the pattern -
- (sens|respons)e and \1ibility --matches "sense and sensibility" and "response and responsibility", but not -"sense and responsibility". If instead the pattern -
- (sens|respons)e and (?1)ibility --is used, it does match "sense and responsibility" as well as the other two -strings. Another example is given in the discussion of DEFINE above. - -
-All subroutine calls, whether recursive or not, are always treated as atomic -groups. That is, once a subroutine has matched some of the subject string, it -is never re-entered, even if it contains untried alternatives and there is a -subsequent matching failure. Any capturing parentheses that are set during the -subroutine call revert to their previous values afterwards. -
--Processing options such as case-independence are fixed when a subpattern is -defined, so if it is used as a subroutine, such options cannot be changed for -different calls. For example, consider this pattern: -
- (abc)(?i:(?-1)) --It matches "abcabc". It does not match "abcABC" because the change of -processing option does not affect the called subpattern. - -
-For compatibility with Oniguruma, the non-Perl syntax \g followed by a name or -a number enclosed either in angle brackets or single quotes, is an alternative -syntax for referencing a subpattern as a subroutine, possibly recursively. Here -are two of the examples used above, rewritten using this syntax: -
- (?<pn> \( ( (?>[^()]+) | \g<pn> )* \) ) - (sens|respons)e and \g'1'ibility --PCRE supports an extension to Oniguruma: if a number is preceded by a -plus or a minus sign it is taken as a relative reference. For example: -
- (abc)(?i:\g<-1>) --Note that \g{...} (Perl syntax) and \g<...> (Oniguruma syntax) are not -synonymous. The former is a back reference; the latter is a subroutine call. - -
-Perl has a feature whereby using the sequence (?{...}) causes arbitrary Perl -code to be obeyed in the middle of matching a regular expression. This makes it -possible, amongst other things, to extract different substrings that match the -same pair of parentheses when there is a repetition. -
--PCRE provides a similar feature, but of course it cannot obey arbitrary Perl -code. The feature is called "callout". The caller of PCRE provides an external -function by putting its entry point in the global variable pcre_callout -(8-bit library) or pcre[16|32]_callout (16-bit or 32-bit library). -By default, this variable contains NULL, which disables all calling out. -
--Within a regular expression, (?C) indicates the points at which the external -function is to be called. If you want to identify different callout points, you -can put a number less than 256 after the letter C. The default value is zero. -For example, this pattern has two callout points: -
- (?C1)abc(?C2)def --If the PCRE_AUTO_CALLOUT flag is passed to a compiling function, callouts are -automatically installed before each item in the pattern. They are all numbered -255. If there is a conditional group in the pattern whose condition is an -assertion, an additional callout is inserted just before the condition. An -explicit callout may also be set at this position, as in this example: -
- (?(?C9)(?=a)abc|def) --Note that this applies only to assertion conditions, not to other types of -condition. - -
-During matching, when PCRE reaches a callout point, the external function is -called. It is provided with the number of the callout, the position in the -pattern, and, optionally, one item of data originally supplied by the caller of -the matching function. The callout function may cause matching to proceed, to -backtrack, or to fail altogether. -
--By default, PCRE implements a number of optimizations at compile time and -matching time, and one side-effect is that sometimes callouts are skipped. If -you need all possible callouts to happen, you need to set options that disable -the relevant optimizations. More details, and a complete description of the -interface to the callout function, are given in the -pcrecallout -documentation. -
--Perl 5.10 introduced a number of "Special Backtracking Control Verbs", which -are still described in the Perl documentation as "experimental and subject to -change or removal in a future version of Perl". It goes on to say: "Their usage -in production code should be noted to avoid problems during upgrades." The same -remarks apply to the PCRE features described in this section. -
--The new verbs make use of what was previously invalid syntax: an opening -parenthesis followed by an asterisk. They are generally of the form -(*VERB) or (*VERB:NAME). Some may take either form, possibly behaving -differently depending on whether or not a name is present. A name is any -sequence of characters that does not include a closing parenthesis. The maximum -length of name is 255 in the 8-bit library and 65535 in the 16-bit and 32-bit -libraries. If the name is empty, that is, if the closing parenthesis -immediately follows the colon, the effect is as if the colon were not there. -Any number of these verbs may occur in a pattern. -
--Since these verbs are specifically related to backtracking, most of them can be -used only when the pattern is to be matched using one of the traditional -matching functions, because these use a backtracking algorithm. With the -exception of (*FAIL), which behaves like a failing negative assertion, the -backtracking control verbs cause an error if encountered by a DFA matching -function. -
--The behaviour of these verbs in -repeated groups, -assertions, -and in -subpatterns called as subroutines -(whether or not recursively) is documented below. -
--PCRE contains some optimizations that are used to speed up matching by running -some checks at the start of each match attempt. For example, it may know the -minimum length of matching subject, or that a particular character must be -present. When one of these optimizations bypasses the running of a match, any -included backtracking verbs will not, of course, be processed. You can suppress -the start-of-match optimizations by setting the PCRE_NO_START_OPTIMIZE option -when calling pcre_compile() or pcre_exec(), or by starting the -pattern with (*NO_START_OPT). There is more discussion of this option in the -section entitled -"Option bits for pcre_exec()" -in the -pcreapi -documentation. -
--Experiments with Perl suggest that it too has similar optimizations, sometimes -leading to anomalous results. -
--The following verbs act as soon as they are encountered. They may not be -followed by a name. -
- (*ACCEPT) --This verb causes the match to end successfully, skipping the remainder of the -pattern. However, when it is inside a subpattern that is called as a -subroutine, only that subpattern is ended successfully. Matching then continues -at the outer level. If (*ACCEPT) in triggered in a positive assertion, the -assertion succeeds; in a negative assertion, the assertion fails. - -
-If (*ACCEPT) is inside capturing parentheses, the data so far is captured. For -example: -
- A((?:A|B(*ACCEPT)|C)D) --This matches "AB", "AAD", or "ACD"; when it matches "AB", "B" is captured by -the outer parentheses. -
- (*FAIL) or (*F) --This verb causes a matching failure, forcing backtracking to occur. It is -equivalent to (?!) but easier to read. The Perl documentation notes that it is -probably useful only when combined with (?{}) or (??{}). Those are, of course, -Perl features that are not present in PCRE. The nearest equivalent is the -callout feature, as for example in this pattern: -
- a+(?C)(*FAIL) --A match with the string "aaaa" always fails, but the callout is taken before -each backtrack happens (in this example, 10 times). - -
-There is one verb whose main purpose is to track how a match was arrived at, -though it also has a secondary use in conjunction with advancing the match -starting point (see (*SKIP) below). -
- (*MARK:NAME) or (*:NAME) --A name is always required with this verb. There may be as many instances of -(*MARK) as you like in a pattern, and their names do not have to be unique. - -
-When a match succeeds, the name of the last-encountered (*MARK:NAME), -(*PRUNE:NAME), or (*THEN:NAME) on the matching path is passed back to the -caller as described in the section entitled -"Extra data for pcre_exec()" -in the -pcreapi -documentation. Here is an example of pcretest output, where the /K -modifier requests the retrieval and outputting of (*MARK) data: -
- re> /X(*MARK:A)Y|X(*MARK:B)Z/K - data> XY - 0: XY - MK: A - XZ - 0: XZ - MK: B --The (*MARK) name is tagged with "MK:" in this output, and in this example it -indicates which of the two alternatives matched. This is a more efficient way -of obtaining this information than putting each alternative in its own -capturing parentheses. - -
-If a verb with a name is encountered in a positive assertion that is true, the -name is recorded and passed back if it is the last-encountered. This does not -happen for negative assertions or failing positive assertions. -
--After a partial match or a failed match, the last encountered name in the -entire match process is returned. For example: -
- re> /X(*MARK:A)Y|X(*MARK:B)Z/K - data> XP - No match, mark = B --Note that in this unanchored example the mark is retained from the match -attempt that started at the letter "X" in the subject. Subsequent match -attempts starting at "P" and then with an empty string do not get as far as the -(*MARK) item, but nevertheless do not reset it. - -
-If you are interested in (*MARK) values after failed matches, you should -probably set the PCRE_NO_START_OPTIMIZE option -(see above) -to ensure that the match is always attempted. -
--The following verbs do nothing when they are encountered. Matching continues -with what follows, but if there is no subsequent match, causing a backtrack to -the verb, a failure is forced. That is, backtracking cannot pass to the left of -the verb. However, when one of these verbs appears inside an atomic group or an -assertion that is true, its effect is confined to that group, because once the -group has been matched, there is never any backtracking into it. In this -situation, backtracking can "jump back" to the left of the entire atomic group -or assertion. (Remember also, as stated above, that this localization also -applies in subroutine calls.) -
--These verbs differ in exactly what kind of failure occurs when backtracking -reaches them. The behaviour described below is what happens when the verb is -not in a subroutine or an assertion. Subsequent sections cover these special -cases. -
- (*COMMIT) --This verb, which may not be followed by a name, causes the whole match to fail -outright if there is a later matching failure that causes backtracking to reach -it. Even if the pattern is unanchored, no further attempts to find a match by -advancing the starting point take place. If (*COMMIT) is the only backtracking -verb that is encountered, once it has been passed pcre_exec() is -committed to finding a match at the current starting point, or not at all. For -example: -
- a+(*COMMIT)b --This matches "xxaab" but not "aacaab". It can be thought of as a kind of -dynamic anchor, or "I've started, so I must finish." The name of the most -recently passed (*MARK) in the path is passed back when (*COMMIT) forces a -match failure. - -
-If there is more than one backtracking verb in a pattern, a different one that -follows (*COMMIT) may be triggered first, so merely passing (*COMMIT) during a -match does not always guarantee that a match must be at this starting point. -
--Note that (*COMMIT) at the start of a pattern is not the same as an anchor, -unless PCRE's start-of-match optimizations are turned off, as shown in this -output from pcretest: -
- re> /(*COMMIT)abc/ - data> xyzabc - 0: abc - data> xyzabc\Y - No match --For this pattern, PCRE knows that any match must start with "a", so the -optimization skips along the subject to "a" before applying the pattern to the -first set of data. The match attempt then succeeds. In the second set of data, -the escape sequence \Y is interpreted by the pcretest program. It causes -the PCRE_NO_START_OPTIMIZE option to be set when pcre_exec() is called. -This disables the optimization that skips along to the first character. The -pattern is now applied starting at "x", and so the (*COMMIT) causes the match -to fail without trying any other starting points. -
- (*PRUNE) or (*PRUNE:NAME) --This verb causes the match to fail at the current starting position in the -subject if there is a later matching failure that causes backtracking to reach -it. If the pattern is unanchored, the normal "bumpalong" advance to the next -starting character then happens. Backtracking can occur as usual to the left of -(*PRUNE), before it is reached, or when matching to the right of (*PRUNE), but -if there is no match to the right, backtracking cannot cross (*PRUNE). In -simple cases, the use of (*PRUNE) is just an alternative to an atomic group or -possessive quantifier, but there are some uses of (*PRUNE) that cannot be -expressed in any other way. In an anchored pattern (*PRUNE) has the same effect -as (*COMMIT). - -
-The behaviour of (*PRUNE:NAME) is the not the same as (*MARK:NAME)(*PRUNE). -It is like (*MARK:NAME) in that the name is remembered for passing back to the -caller. However, (*SKIP:NAME) searches only for names set with (*MARK). -
- (*SKIP) --This verb, when given without a name, is like (*PRUNE), except that if the -pattern is unanchored, the "bumpalong" advance is not to the next character, -but to the position in the subject where (*SKIP) was encountered. (*SKIP) -signifies that whatever text was matched leading up to it cannot be part of a -successful match. Consider: -
- a+(*SKIP)b --If the subject is "aaaac...", after the first match attempt fails (starting at -the first character in the string), the starting point skips on to start the -next attempt at "c". Note that a possessive quantifer does not have the same -effect as this example; although it would suppress backtracking during the -first match attempt, the second attempt would start at the second character -instead of skipping on to "c". -
- (*SKIP:NAME) --When (*SKIP) has an associated name, its behaviour is modified. When it is -triggered, the previous path through the pattern is searched for the most -recent (*MARK) that has the same name. If one is found, the "bumpalong" advance -is to the subject position that corresponds to that (*MARK) instead of to where -(*SKIP) was encountered. If no (*MARK) with a matching name is found, the -(*SKIP) is ignored. - -
-Note that (*SKIP:NAME) searches only for names set by (*MARK:NAME). It ignores -names that are set by (*PRUNE:NAME) or (*THEN:NAME). -
- (*THEN) or (*THEN:NAME) --This verb causes a skip to the next innermost alternative when backtracking -reaches it. That is, it cancels any further backtracking within the current -alternative. Its name comes from the observation that it can be used for a -pattern-based if-then-else block: -
- ( COND1 (*THEN) FOO | COND2 (*THEN) BAR | COND3 (*THEN) BAZ ) ... --If the COND1 pattern matches, FOO is tried (and possibly further items after -the end of the group if FOO succeeds); on failure, the matcher skips to the -second alternative and tries COND2, without backtracking into COND1. If that -succeeds and BAR fails, COND3 is tried. If subsequently BAZ fails, there are no -more alternatives, so there is a backtrack to whatever came before the entire -group. If (*THEN) is not inside an alternation, it acts like (*PRUNE). - -
-The behaviour of (*THEN:NAME) is the not the same as (*MARK:NAME)(*THEN). -It is like (*MARK:NAME) in that the name is remembered for passing back to the -caller. However, (*SKIP:NAME) searches only for names set with (*MARK). -
--A subpattern that does not contain a | character is just a part of the -enclosing alternative; it is not a nested alternation with only one -alternative. The effect of (*THEN) extends beyond such a subpattern to the -enclosing alternative. Consider this pattern, where A, B, etc. are complex -pattern fragments that do not contain any | characters at this level: -
- A (B(*THEN)C) | D --If A and B are matched, but there is a failure in C, matching does not -backtrack into A; instead it moves to the next alternative, that is, D. -However, if the subpattern containing (*THEN) is given an alternative, it -behaves differently: -
- A (B(*THEN)C | (*FAIL)) | D --The effect of (*THEN) is now confined to the inner subpattern. After a failure -in C, matching moves to (*FAIL), which causes the whole subpattern to fail -because there are no more alternatives to try. In this case, matching does now -backtrack into A. - -
-Note that a conditional subpattern is not considered as having two -alternatives, because only one is ever used. In other words, the | character in -a conditional subpattern has a different meaning. Ignoring white space, -consider: -
- ^.*? (?(?=a) a | b(*THEN)c ) --If the subject is "ba", this pattern does not match. Because .*? is ungreedy, -it initially matches zero characters. The condition (?=a) then fails, the -character "b" is matched, but "c" is not. At this point, matching does not -backtrack to .*? as might perhaps be expected from the presence of the | -character. The conditional subpattern is part of the single alternative that -comprises the whole pattern, and so the match fails. (If there was a backtrack -into .*?, allowing it to match "b", the match would succeed.) - -
-The verbs just described provide four different "strengths" of control when -subsequent matching fails. (*THEN) is the weakest, carrying on the match at the -next alternative. (*PRUNE) comes next, failing the match at the current -starting position, but allowing an advance to the next character (for an -unanchored pattern). (*SKIP) is similar, except that the advance may be more -than one character. (*COMMIT) is the strongest, causing the entire match to -fail. -
--If more than one backtracking verb is present in a pattern, the one that is -backtracked onto first acts. For example, consider this pattern, where A, B, -etc. are complex pattern fragments: -
- (A(*COMMIT)B(*THEN)C|ABD) --If A matches but B fails, the backtrack to (*COMMIT) causes the entire match to -fail. However, if A and B match, but C fails, the backtrack to (*THEN) causes -the next alternative (ABD) to be tried. This behaviour is consistent, but is -not always the same as Perl's. It means that if two or more backtracking verbs -appear in succession, all the the last of them has no effect. Consider this -example: -
- ...(*COMMIT)(*PRUNE)... --If there is a matching failure to the right, backtracking onto (*PRUNE) causes -it to be triggered, and its action is taken. There can never be a backtrack -onto (*COMMIT). - -
-PCRE differs from Perl in its handling of backtracking verbs in repeated -groups. For example, consider: -
- /(a(*COMMIT)b)+ac/ --If the subject is "abac", Perl matches, but PCRE fails because the (*COMMIT) in -the second repeat of the group acts. - -
-(*FAIL) in an assertion has its normal effect: it forces an immediate backtrack. -
--(*ACCEPT) in a positive assertion causes the assertion to succeed without any -further processing. In a negative assertion, (*ACCEPT) causes the assertion to -fail without any further processing. -
--The other backtracking verbs are not treated specially if they appear in a -positive assertion. In particular, (*THEN) skips to the next alternative in the -innermost enclosing group that has alternations, whether or not this is within -the assertion. -
--Negative assertions are, however, different, in order to ensure that changing a -positive assertion into a negative assertion changes its result. Backtracking -into (*COMMIT), (*SKIP), or (*PRUNE) causes a negative assertion to be true, -without considering any further alternative branches in the assertion. -Backtracking into (*THEN) causes it to skip to the next enclosing alternative -within the assertion (the normal behaviour), but if the assertion does not have -such an alternative, (*THEN) behaves like (*PRUNE). -
--These behaviours occur whether or not the subpattern is called recursively. -Perl's treatment of subroutines is different in some cases. -
--(*FAIL) in a subpattern called as a subroutine has its normal effect: it forces -an immediate backtrack. -
--(*ACCEPT) in a subpattern called as a subroutine causes the subroutine match to -succeed without any further processing. Matching then continues after the -subroutine call. -
--(*COMMIT), (*SKIP), and (*PRUNE) in a subpattern called as a subroutine cause -the subroutine match to fail. -
--(*THEN) skips to the next alternative in the innermost enclosing group within -the subpattern that has alternatives. If there is no such group within the -subpattern, (*THEN) causes the subroutine match to fail. -
--pcreapi(3), pcrecallout(3), pcrematching(3), -pcresyntax(3), pcre(3), pcre16(3), pcre32(3). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 23 October 2016
-
-Copyright © 1997-2016 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcreperform.html b/libs/Pcre16/docs/doc/html/pcreperform.html deleted file mode 100644 index dda207f901..0000000000 --- a/libs/Pcre16/docs/doc/html/pcreperform.html +++ /dev/null @@ -1,195 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-PCRE PERFORMANCE
-
-
-Two aspects of performance are discussed below: memory usage and processing -time. The way you express your pattern as a regular expression can affect both -of them. -
--Patterns are compiled by PCRE into a reasonably efficient interpretive code, so -that most simple patterns do not use much memory. However, there is one case -where the memory usage of a compiled pattern can be unexpectedly large. If a -parenthesized subpattern has a quantifier with a minimum greater than 1 and/or -a limited maximum, the whole subpattern is repeated in the compiled code. For -example, the pattern -
- (abc|def){2,4} --is compiled as if it were -
- (abc|def)(abc|def)((abc|def)(abc|def)?)? --(Technical aside: It is done this way so that backtrack points within each of -the repetitions can be independently maintained.) - -
-For regular expressions whose quantifiers use only small numbers, this is not -usually a problem. However, if the numbers are large, and particularly if such -repetitions are nested, the memory usage can become an embarrassment. For -example, the very simple pattern -
- ((ab){1,1000}c){1,3} --uses 51K bytes when compiled using the 8-bit library. When PCRE is compiled -with its default internal pointer size of two bytes, the size limit on a -compiled pattern is 64K data units, and this is reached with the above pattern -if the outer repetition is increased from 3 to 4. PCRE can be compiled to use -larger internal pointers and thus handle larger compiled patterns, but it is -better to try to rewrite your pattern to use less memory if you can. - -
-One way of reducing the memory usage for such patterns is to make use of PCRE's -"subroutine" -facility. Re-writing the above pattern as -
- ((ab)(?2){0,999}c)(?1){0,2} --reduces the memory requirements to 18K, and indeed it remains under 20K even -with the outer repetition increased to 100. However, this pattern is not -exactly equivalent, because the "subroutine" calls are treated as -atomic groups -into which there can be no backtracking if there is a subsequent matching -failure. Therefore, PCRE cannot do this kind of rewriting automatically. -Furthermore, there is a noticeable loss of speed when executing the modified -pattern. Nevertheless, if the atomic grouping is not a problem and the loss of -speed is acceptable, this kind of rewriting will allow you to process patterns -that PCRE cannot otherwise handle. - -
-When pcre_exec() or pcre[16|32]_exec() is used for matching, certain -kinds of pattern can cause it to use large amounts of the process stack. In -some environments the default process stack is quite small, and if it runs out -the result is often SIGSEGV. This issue is probably the most frequently raised -problem with PCRE. Rewriting your pattern can often help. The -pcrestack -documentation discusses this issue in detail. -
--Certain items in regular expression patterns are processed more efficiently -than others. It is more efficient to use a character class like [aeiou] than a -set of single-character alternatives such as (a|e|i|o|u). In general, the -simplest construction that provides the required behaviour is usually the most -efficient. Jeffrey Friedl's book contains a lot of useful general discussion -about optimizing regular expressions for efficient performance. This document -contains a few observations about PCRE. -
--Using Unicode character properties (the \p, \P, and \X escapes) is slow, -because PCRE has to use a multi-stage table lookup whenever it needs a -character's property. If you can find an alternative pattern that does not use -character properties, it will probably be faster. -
--By default, the escape sequences \b, \d, \s, and \w, and the POSIX -character classes such as [:alpha:] do not use Unicode properties, partly for -backwards compatibility, and partly for performance reasons. However, you can -set PCRE_UCP if you want Unicode character properties to be used. This can -double the matching time for items such as \d, when matched with -a traditional matching function; the performance loss is less with -a DFA matching function, and in both cases there is not much difference for -\b. -
--When a pattern begins with .* not in parentheses, or in parentheses that are -not the subject of a backreference, and the PCRE_DOTALL option is set, the -pattern is implicitly anchored by PCRE, since it can match only at the start of -a subject string. However, if PCRE_DOTALL is not set, PCRE cannot make this -optimization, because the . metacharacter does not then match a newline, and if -the subject string contains newlines, the pattern may match from the character -immediately following one of them instead of from the very start. For example, -the pattern -
- .*second --matches the subject "first\nand second" (where \n stands for a newline -character), with the match starting at the seventh character. In order to do -this, PCRE has to retry the match starting after every newline in the subject. - -
-If you are using such a pattern with subject strings that do not contain -newlines, the best performance is obtained by setting PCRE_DOTALL, or starting -the pattern with ^.* or ^.*? to indicate explicit anchoring. That saves PCRE -from having to scan along the subject looking for a newline to restart at. -
--Beware of patterns that contain nested indefinite repeats. These can take a -long time to run when applied to a string that does not match. Consider the -pattern fragment -
- ^(a+)* --This can match "aaaa" in 16 different ways, and this number increases very -rapidly as the string gets longer. (The * repeat can match 0, 1, 2, 3, or 4 -times, and for each of those cases other than 0 or 4, the + repeats can match -different numbers of times.) When the remainder of the pattern is such that the -entire match is going to fail, PCRE has in principle to try every possible -variation, and this can take an extremely long time, even for relatively short -strings. - -
-An optimization catches some of the more simple cases such as -
- (a+)*b --where a literal character follows. Before embarking on the standard matching -procedure, PCRE checks that there is a "b" later in the subject string, and if -there is not, it fails the match immediately. However, when there is no -following literal this optimization cannot be used. You can see the difference -by comparing the behaviour of -
- (a+)*\d --with the pattern above. The former gives a failure almost instantly when -applied to a whole line of "a" characters, whereas the latter takes an -appreciable time with strings longer than about 20 characters. - -
-In many cases, the solution to this kind of performance issue is to use an -atomic group or a possessive quantifier. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 25 August 2012
-
-Copyright © 1997-2012 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcreposix.html b/libs/Pcre16/docs/doc/html/pcreposix.html deleted file mode 100644 index 18924cf7f9..0000000000 --- a/libs/Pcre16/docs/doc/html/pcreposix.html +++ /dev/null @@ -1,290 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-#include <pcreposix.h> -
-
-int regcomp(regex_t *preg, const char *pattern,
- int cflags);
-
-
-int regexec(regex_t *preg, const char *string,
- size_t nmatch, regmatch_t pmatch[], int eflags);
- size_t regerror(int errcode, const regex_t *preg,
- char *errbuf, size_t errbuf_size);
-
-
-void regfree(regex_t *preg);
-
-This set of functions provides a POSIX-style API for the PCRE regular -expression 8-bit library. See the -pcreapi -documentation for a description of PCRE's native API, which contains much -additional functionality. There is no POSIX-style wrapper for PCRE's 16-bit -and 32-bit library. -
--The functions described here are just wrapper functions that ultimately call -the PCRE native API. Their prototypes are defined in the pcreposix.h -header file, and on Unix systems the library itself is called -pcreposix.a, so can be accessed by adding -lpcreposix to the -command for linking an application that uses them. Because the POSIX functions -call the native ones, it is also necessary to add -lpcre. -
--I have implemented only those POSIX option bits that can be reasonably mapped -to PCRE native options. In addition, the option REG_EXTENDED is defined with -the value zero. This has no effect, but since programs that are written to the -POSIX interface often use it, this makes it easier to slot in PCRE as a -replacement library. Other POSIX options are not even defined. -
--There are also some other options that are not defined by POSIX. These have -been added at the request of users who want to make use of certain -PCRE-specific features via the POSIX calling interface. -
--When PCRE is called via these functions, it is only the API that is POSIX-like -in style. The syntax and semantics of the regular expressions themselves are -still those of Perl, subject to the setting of various PCRE options, as -described below. "POSIX-like in style" means that the API approximates to the -POSIX definition; it is not fully POSIX-compatible, and in multi-byte encoding -domains it is probably even less compatible. -
--The header for these functions is supplied as pcreposix.h to avoid any -potential clash with other POSIX libraries. It can, of course, be renamed or -aliased as regex.h, which is the "correct" name. It provides two -structure types, regex_t for compiled internal forms, and -regmatch_t for returning captured substrings. It also defines some -constants whose names start with "REG_"; these are used for setting options and -identifying error codes. -
--The function regcomp() is called to compile a pattern into an -internal form. The pattern is a C string terminated by a binary zero, and -is passed in the argument pattern. The preg argument is a pointer -to a regex_t structure that is used as a base for storing information -about the compiled regular expression. -
--The argument cflags is either zero, or contains one or more of the bits -defined by the following macros: -
- REG_DOTALL --The PCRE_DOTALL option is set when the regular expression is passed for -compilation to the native function. Note that REG_DOTALL is not part of the -POSIX standard. -
- REG_ICASE --The PCRE_CASELESS option is set when the regular expression is passed for -compilation to the native function. -
- REG_NEWLINE --The PCRE_MULTILINE option is set when the regular expression is passed for -compilation to the native function. Note that this does not mimic the -defined POSIX behaviour for REG_NEWLINE (see the following section). -
- REG_NOSUB --The PCRE_NO_AUTO_CAPTURE option is set when the regular expression is passed -for compilation to the native function. In addition, when a pattern that is -compiled with this flag is passed to regexec() for matching, the -nmatch and pmatch arguments are ignored, and no captured strings -are returned. -
- REG_UCP --The PCRE_UCP option is set when the regular expression is passed for -compilation to the native function. This causes PCRE to use Unicode properties -when matchine \d, \w, etc., instead of just recognizing ASCII values. Note -that REG_UTF8 is not part of the POSIX standard. -
- REG_UNGREEDY --The PCRE_UNGREEDY option is set when the regular expression is passed for -compilation to the native function. Note that REG_UNGREEDY is not part of the -POSIX standard. -
- REG_UTF8 --The PCRE_UTF8 option is set when the regular expression is passed for -compilation to the native function. This causes the pattern itself and all data -strings used for matching it to be treated as UTF-8 strings. Note that REG_UTF8 -is not part of the POSIX standard. - -
-In the absence of these flags, no options are passed to the native function. -This means the the regex is compiled with PCRE default semantics. In -particular, the way it handles newline characters in the subject string is the -Perl way, not the POSIX way. Note that setting PCRE_MULTILINE has only -some of the effects specified for REG_NEWLINE. It does not affect the way -newlines are matched by . (they are not) or by a negative class such as [^a] -(they are). -
--The yield of regcomp() is zero on success, and non-zero otherwise. The -preg structure is filled in on success, and one member of the structure -is public: re_nsub contains the number of capturing subpatterns in -the regular expression. Various error codes are defined in the header file. -
--NOTE: If the yield of regcomp() is non-zero, you must not attempt to -use the contents of the preg structure. If, for example, you pass it to -regexec(), the result is undefined and your program is likely to crash. -
--This area is not simple, because POSIX and Perl take different views of things. -It is not possible to get PCRE to obey POSIX semantics, but then PCRE was never -intended to be a POSIX engine. The following table lists the different -possibilities for matching newline characters in PCRE: -
- Default Change with - - . matches newline no PCRE_DOTALL - newline matches [^a] yes not changeable - $ matches \n at end yes PCRE_DOLLARENDONLY - $ matches \n in middle no PCRE_MULTILINE - ^ matches \n in middle no PCRE_MULTILINE --This is the equivalent table for POSIX: -
- Default Change with - - . matches newline yes REG_NEWLINE - newline matches [^a] yes REG_NEWLINE - $ matches \n at end no REG_NEWLINE - $ matches \n in middle no REG_NEWLINE - ^ matches \n in middle no REG_NEWLINE --PCRE's behaviour is the same as Perl's, except that there is no equivalent for -PCRE_DOLLAR_ENDONLY in Perl. In both PCRE and Perl, there is no way to stop -newline from matching [^a]. - -
-The default POSIX newline handling can be obtained by setting PCRE_DOTALL and -PCRE_DOLLAR_ENDONLY, but there is no way to make PCRE behave exactly as for the -REG_NEWLINE action. -
--The function regexec() is called to match a compiled pattern preg -against a given string, which is by default terminated by a zero byte -(but see REG_STARTEND below), subject to the options in eflags. These can -be: -
- REG_NOTBOL --The PCRE_NOTBOL option is set when calling the underlying PCRE matching -function. -
- REG_NOTEMPTY --The PCRE_NOTEMPTY option is set when calling the underlying PCRE matching -function. Note that REG_NOTEMPTY is not part of the POSIX standard. However, -setting this option can give more POSIX-like behaviour in some situations. -
- REG_NOTEOL --The PCRE_NOTEOL option is set when calling the underlying PCRE matching -function. -
- REG_STARTEND --The string is considered to start at string + pmatch[0].rm_so and -to have a terminating NUL located at string + pmatch[0].rm_eo -(there need not actually be a NUL at that location), regardless of the value of -nmatch. This is a BSD extension, compatible with but not specified by -IEEE Standard 1003.2 (POSIX.2), and should be used with caution in software -intended to be portable to other systems. Note that a non-zero rm_so does -not imply REG_NOTBOL; REG_STARTEND affects only the location of the string, not -how it is matched. - -
-If the pattern was compiled with the REG_NOSUB flag, no data about any matched -strings is returned. The nmatch and pmatch arguments of -regexec() are ignored. -
--If the value of nmatch is zero, or if the value pmatch is NULL, -no data about any matched strings is returned. -
--Otherwise,the portion of the string that was matched, and also any captured -substrings, are returned via the pmatch argument, which points to an -array of nmatch structures of type regmatch_t, containing the -members rm_so and rm_eo. These contain the offset to the first -character of each substring and the offset to the first character after the end -of each substring, respectively. The 0th element of the vector relates to the -entire portion of string that was matched; subsequent elements relate to -the capturing subpatterns of the regular expression. Unused entries in the -array have both structure members set to -1. -
--A successful match yields a zero return; various error codes are defined in the -header file, of which REG_NOMATCH is the "expected" failure code. -
--The regerror() function maps a non-zero errorcode from either -regcomp() or regexec() to a printable message. If preg is not -NULL, the error should have arisen from the use of that structure. A message -terminated by a binary zero is placed in errbuf. The length of the -message, including the zero, is limited to errbuf_size. The yield of the -function is the size of buffer needed to hold the whole message. -
--Compiling a regular expression causes memory to be allocated and associated -with the preg structure. The function regfree() frees all such -memory, after which preg may no longer be used as a compiled expression. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 09 January 2012
-
-Copyright © 1997-2012 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcreprecompile.html b/libs/Pcre16/docs/doc/html/pcreprecompile.html deleted file mode 100644 index decb1d6ce0..0000000000 --- a/libs/Pcre16/docs/doc/html/pcreprecompile.html +++ /dev/null @@ -1,163 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-If you are running an application that uses a large number of regular -expression patterns, it may be useful to store them in a precompiled form -instead of having to compile them every time the application is run. -If you are not using any private character tables (see the -pcre_maketables() -documentation), this is relatively straightforward. If you are using private -tables, it is a little bit more complicated. However, if you are using the -just-in-time optimization feature, it is not possible to save and reload the -JIT data. -
--If you save compiled patterns to a file, you can copy them to a different host -and run them there. If the two hosts have different endianness (byte order), -you should run the pcre[16|32]_pattern_to_host_byte_order() function on the -new host before trying to match the pattern. The matching functions return -PCRE_ERROR_BADENDIANNESS if they detect a pattern with the wrong endianness. -
--Compiling regular expressions with one version of PCRE for use with a different -version is not guaranteed to work and may cause crashes, and saving and -restoring a compiled pattern loses any JIT optimization data. -
--The value returned by pcre[16|32]_compile() points to a single block of -memory that holds the compiled pattern and associated data. You can find the -length of this block in bytes by calling pcre[16|32]_fullinfo() with an -argument of PCRE_INFO_SIZE. You can then save the data in any appropriate -manner. Here is sample code for the 8-bit library that compiles a pattern and -writes it to a file. It assumes that the variable fd refers to a file -that is open for output: -
- int erroroffset, rc, size; - char *error; - pcre *re; - - re = pcre_compile("my pattern", 0, &error, &erroroffset, NULL); - if (re == NULL) { ... handle errors ... } - rc = pcre_fullinfo(re, NULL, PCRE_INFO_SIZE, &size); - if (rc < 0) { ... handle errors ... } - rc = fwrite(re, 1, size, fd); - if (rc != size) { ... handle errors ... } --In this example, the bytes that comprise the compiled pattern are copied -exactly. Note that this is binary data that may contain any of the 256 possible -byte values. On systems that make a distinction between binary and non-binary -data, be sure that the file is opened for binary output. - -
-If you want to write more than one pattern to a file, you will have to devise a -way of separating them. For binary data, preceding each pattern with its length -is probably the most straightforward approach. Another possibility is to write -out the data in hexadecimal instead of binary, one pattern to a line. -
--Saving compiled patterns in a file is only one possible way of storing them for -later use. They could equally well be saved in a database, or in the memory of -some daemon process that passes them via sockets to the processes that want -them. -
--If the pattern has been studied, it is also possible to save the normal study -data in a similar way to the compiled pattern itself. However, if the -PCRE_STUDY_JIT_COMPILE was used, the just-in-time data that is created cannot -be saved because it is too dependent on the current environment. When studying -generates additional information, pcre[16|32]_study() returns a pointer to a -pcre[16|32]_extra data block. Its format is defined in the -section on matching a pattern -in the -pcreapi -documentation. The study_data field points to the binary study data, and -this is what you must save (not the pcre[16|32]_extra block itself). The -length of the study data can be obtained by calling pcre[16|32]_fullinfo() -with an argument of PCRE_INFO_STUDYSIZE. Remember to check that -pcre[16|32]_study() did return a non-NULL value before trying to save the -study data. -
--Re-using a precompiled pattern is straightforward. Having reloaded it into main -memory, called pcre[16|32]_pattern_to_host_byte_order() if necessary, you -pass its pointer to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() in -the usual way. -
--However, if you passed a pointer to custom character tables when the pattern -was compiled (the tableptr argument of pcre[16|32]_compile()), you -must now pass a similar pointer to pcre[16|32]_exec() or -pcre[16|32]_dfa_exec(), because the value saved with the compiled pattern -will obviously be nonsense. A field in a pcre[16|32]_extra() block is used -to pass this data, as described in the -section on matching a pattern -in the -pcreapi -documentation. -
--Warning: The tables that pcre_exec() and pcre_dfa_exec() use -must be the same as those that were used when the pattern was compiled. If this -is not the case, the behaviour is undefined. -
--If you did not provide custom character tables when the pattern was compiled, -the pointer in the compiled pattern is NULL, which causes the matching -functions to use PCRE's internal tables. Thus, you do not need to take any -special action at run time in this case. -
--If you saved study data with the compiled pattern, you need to create your own -pcre[16|32]_extra data block and set the study_data field to point -to the reloaded study data. You must also set the PCRE_EXTRA_STUDY_DATA bit in -the flags field to indicate that study data is present. Then pass the -pcre[16|32]_extra block to the matching function in the usual way. If the -pattern was studied for just-in-time optimization, that data cannot be saved, -and so is lost by a save/restore cycle. -
--In general, it is safest to recompile all saved patterns when you update to a -new PCRE release, though not all updates actually require this. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 12 November 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcresample.html b/libs/Pcre16/docs/doc/html/pcresample.html deleted file mode 100644 index aca9184e00..0000000000 --- a/libs/Pcre16/docs/doc/html/pcresample.html +++ /dev/null @@ -1,110 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-PCRE SAMPLE PROGRAM
-
-
-A simple, complete demonstration program, to get you started with using PCRE, -is supplied in the file pcredemo.c in the PCRE distribution. A listing of -this program is given in the -pcredemo -documentation. If you do not have a copy of the PCRE distribution, you can save -this listing to re-create pcredemo.c. -
--The demonstration program, which uses the original PCRE 8-bit library, compiles -the regular expression that is its first argument, and matches it against the -subject string in its second argument. No PCRE options are set, and default -character tables are used. If matching succeeds, the program outputs the -portion of the subject that matched, together with the contents of any captured -substrings. -
--If the -g option is given on the command line, the program then goes on to -check for further matches of the same regular expression in the same subject -string. The logic is a little bit tricky because of the possibility of matching -an empty string. Comments in the code explain what is going on. -
--If PCRE is installed in the standard include and library directories for your -operating system, you should be able to compile the demonstration program using -this command: -
- gcc -o pcredemo pcredemo.c -lpcre --If PCRE is installed elsewhere, you may need to add additional options to the -command line. For example, on a Unix-like system that has PCRE installed in -/usr/local, you can compile the demonstration program using a command -like this: -
- gcc -o pcredemo -I/usr/local/include pcredemo.c -L/usr/local/lib -lpcre --In a Windows environment, if you want to statically link the program against a -non-dll pcre.a file, you must uncomment the line that defines PCRE_STATIC -before including pcre.h, because otherwise the pcre_malloc() and -pcre_free() exported functions will be declared -__declspec(dllimport), with unwanted results. - -
-Once you have compiled and linked the demonstration program, you can run simple -tests like this: -
- ./pcredemo 'cat|dog' 'the cat sat on the mat' - ./pcredemo -g 'cat|dog' 'the dog sat on the cat' --Note that there is a much more comprehensive test program, called -pcretest, -which supports many more facilities for testing regular expressions and both -PCRE libraries. The -pcredemo -program is provided as a simple coding example. - -
-If you try to run -pcredemo -when PCRE is not installed in the standard library directory, you may get an -error like this on some operating systems (e.g. Solaris): -
- ld.so.1: a.out: fatal: libpcre.so.0: open failed: No such file or directory --This is caused by the way shared library support works on those systems. You -need to add -
- -R/usr/local/lib --(for example) to the compile command to get round this problem. - -
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 10 January 2012
-
-Copyright © 1997-2012 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcrestack.html b/libs/Pcre16/docs/doc/html/pcrestack.html deleted file mode 100644 index af6406d070..0000000000 --- a/libs/Pcre16/docs/doc/html/pcrestack.html +++ /dev/null @@ -1,225 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-PCRE DISCUSSION OF STACK USAGE
-
-
-When you call pcre[16|32]_exec(), it makes use of an internal function -called match(). This calls itself recursively at branch points in the -pattern, in order to remember the state of the match so that it can back up and -try a different alternative if the first one fails. As matching proceeds deeper -and deeper into the tree of possibilities, the recursion depth increases. The -match() function is also called in other circumstances, for example, -whenever a parenthesized sub-pattern is entered, and in certain cases of -repetition. -
--Not all calls of match() increase the recursion depth; for an item such -as a* it may be called several times at the same level, after matching -different numbers of a's. Furthermore, in a number of cases where the result of -the recursive call would immediately be passed back as the result of the -current call (a "tail recursion"), the function is just restarted instead. -
--The above comments apply when pcre[16|32]_exec() is run in its normal -interpretive manner. If the pattern was studied with the -PCRE_STUDY_JIT_COMPILE option, and just-in-time compiling was successful, and -the options passed to pcre[16|32]_exec() were not incompatible, the matching -process uses the JIT-compiled code instead of the match() function. In -this case, the memory requirements are handled entirely differently. See the -pcrejit -documentation for details. -
--The pcre[16|32]_dfa_exec() function operates in an entirely different way, -and uses recursion only when there is a regular expression recursion or -subroutine call in the pattern. This includes the processing of assertion and -"once-only" subpatterns, which are handled like subroutine calls. Normally, -these are never very deep, and the limit on the complexity of -pcre[16|32]_dfa_exec() is controlled by the amount of workspace it is given. -However, it is possible to write patterns with runaway infinite recursions; -such patterns will cause pcre[16|32]_dfa_exec() to run out of stack. At -present, there is no protection against this. -
--The comments that follow do NOT apply to pcre[16|32]_dfa_exec(); they are -relevant only for pcre[16|32]_exec() without the JIT optimization. -
--Each time that match() is actually called recursively, it uses memory -from the process stack. For certain kinds of pattern and data, very large -amounts of stack may be needed, despite the recognition of "tail recursion". -You can often reduce the amount of recursion, and therefore the amount of stack -used, by modifying the pattern that is being matched. Consider, for example, -this pattern: -
- ([^<]|<(?!inet))+ --It matches from wherever it starts until it encounters "<inet" or the end of -the data, and is the kind of pattern that might be used when processing an XML -file. Each iteration of the outer parentheses matches either one character that -is not "<" or a "<" that is not followed by "inet". However, each time a -parenthesis is processed, a recursion occurs, so this formulation uses a stack -frame for each matched character. For a long string, a lot of stack is -required. Consider now this rewritten pattern, which matches exactly the same -strings: -
- ([^<]++|<(?!inet))+ --This uses very much less stack, because runs of characters that do not contain -"<" are "swallowed" in one item inside the parentheses. Recursion happens only -when a "<" character that is not followed by "inet" is encountered (and we -assume this is relatively rare). A possessive quantifier is used to stop any -backtracking into the runs of non-"<" characters, but that is not related to -stack usage. - -
-This example shows that one way of avoiding stack problems when matching long -subject strings is to write repeated parenthesized subpatterns to match more -than one character whenever possible. -
--In environments where stack memory is constrained, you might want to compile -PCRE to use heap memory instead of stack for remembering back-up points when -pcre[16|32]_exec() is running. This makes it run a lot more slowly, however. -Details of how to do this are given in the -pcrebuild -documentation. When built in this way, instead of using the stack, PCRE obtains -and frees memory by calling the functions that are pointed to by the -pcre[16|32]_stack_malloc and pcre[16|32]_stack_free variables. By -default, these point to malloc() and free(), but you can replace -the pointers to cause PCRE to use your own functions. Since the block sizes are -always the same, and are always freed in reverse order, it may be possible to -implement customized memory handlers that are more efficient than the standard -functions. -
--You can set limits on the number of times that match() is called, both in -total and recursively. If a limit is exceeded, pcre[16|32]_exec() returns an -error code. Setting suitable limits should prevent it from running out of -stack. The default values of the limits are very large, and unlikely ever to -operate. They can be changed when PCRE is built, and they can also be set when -pcre[16|32]_exec() is called. For details of these interfaces, see the -pcrebuild -documentation and the -section on extra data for pcre[16|32]_exec() -in the -pcreapi -documentation. -
--As a very rough rule of thumb, you should reckon on about 500 bytes per -recursion. Thus, if you want to limit your stack usage to 8Mb, you should set -the limit at 16000 recursions. A 64Mb stack, on the other hand, can support -around 128000 recursions. -
--In Unix-like environments, the pcretest test program has a command line -option (-S) that can be used to increase the size of its stack. As long -as the stack is large enough, another option (-M) can be used to find the -smallest limits that allow a particular pattern to match a given subject -string. This is done by calling pcre[16|32]_exec() repeatedly with different -limits. -
--The actual amount of stack used per recursion can vary quite a lot, depending -on the compiler that was used to build PCRE and the optimization or debugging -options that were set for it. The rule of thumb value of 500 bytes mentioned -above may be larger or smaller than what is actually needed. A better -approximation can be obtained by running this command: -
- pcretest -m -C --The -C option causes pcretest to output information about the -options with which PCRE was compiled. When -m is also given (before --C), information about stack use is given in a line like this: -
- Match recursion uses stack: approximate frame size = 640 bytes --The value is approximate because some recursions need a bit more (up to perhaps -16 more bytes). - -
-If the above command is given when PCRE is compiled to use the heap instead of -the stack for recursion, the value that is output is the size of each block -that is obtained from the heap. -
--In Unix-like environments, there is not often a problem with the stack unless -very long strings are involved, though the default limit on stack size varies -from system to system. Values from 8Mb to 64Mb are common. You can find your -default limit by running the command: -
- ulimit -s --Unfortunately, the effect of running out of stack is often SIGSEGV, though -sometimes a more explicit error message is given. You can normally increase the -limit on stack size by code such as this: -
- struct rlimit rlim; - getrlimit(RLIMIT_STACK, &rlim); - rlim.rlim_cur = 100*1024*1024; - setrlimit(RLIMIT_STACK, &rlim); --This reads the current limits (soft and hard) using getrlimit(), then -attempts to increase the soft limit to 100Mb using setrlimit(). You must -do this before calling pcre[16|32]_exec(). - -
-Using setrlimit(), as described above, should also work on Mac OS X. It -is also possible to set a stack size when linking a program. There is a -discussion about stack sizes in Mac OS X at this web site: -http://developer.apple.com/qa/qa2005/qa1419.html. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 24 June 2012
-
-Copyright © 1997-2012 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcresyntax.html b/libs/Pcre16/docs/doc/html/pcresyntax.html deleted file mode 100644 index 5896b9e068..0000000000 --- a/libs/Pcre16/docs/doc/html/pcresyntax.html +++ /dev/null @@ -1,561 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-The full syntax and semantics of the regular expressions that are supported by -PCRE are described in the -pcrepattern -documentation. This document contains a quick-reference summary of the syntax. -
--
- \x where x is non-alphanumeric is a literal x - \Q...\E treat enclosed characters as literal -- -
-
- \a alarm, that is, the BEL character (hex 07) - \cx "control-x", where x is any ASCII character - \e escape (hex 1B) - \f form feed (hex 0C) - \n newline (hex 0A) - \r carriage return (hex 0D) - \t tab (hex 09) - \0dd character with octal code 0dd - \ddd character with octal code ddd, or backreference - \o{ddd..} character with octal code ddd.. - \xhh character with hex code hh - \x{hhh..} character with hex code hhh.. --Note that \0dd is always an octal code, and that \8 and \9 are the literal -characters "8" and "9". - -
-
- . any character except newline; - in dotall mode, any character whatsoever - \C one data unit, even in UTF mode (best avoided) - \d a decimal digit - \D a character that is not a decimal digit - \h a horizontal white space character - \H a character that is not a horizontal white space character - \N a character that is not a newline - \p{xx} a character with the xx property - \P{xx} a character without the xx property - \R a newline sequence - \s a white space character - \S a character that is not a white space character - \v a vertical white space character - \V a character that is not a vertical white space character - \w a "word" character - \W a "non-word" character - \X a Unicode extended grapheme cluster --By default, \d, \s, and \w match only ASCII characters, even in UTF-8 mode -or in the 16- bit and 32-bit libraries. However, if locale-specific matching is -happening, \s and \w may also match characters with code points in the range -128-255. If the PCRE_UCP option is set, the behaviour of these escape sequences -is changed to use Unicode properties and they match many more characters. - -
-
- C Other - Cc Control - Cf Format - Cn Unassigned - Co Private use - Cs Surrogate - - L Letter - Ll Lower case letter - Lm Modifier letter - Lo Other letter - Lt Title case letter - Lu Upper case letter - L& Ll, Lu, or Lt - - M Mark - Mc Spacing mark - Me Enclosing mark - Mn Non-spacing mark - - N Number - Nd Decimal number - Nl Letter number - No Other number - - P Punctuation - Pc Connector punctuation - Pd Dash punctuation - Pe Close punctuation - Pf Final punctuation - Pi Initial punctuation - Po Other punctuation - Ps Open punctuation - - S Symbol - Sc Currency symbol - Sk Modifier symbol - Sm Mathematical symbol - So Other symbol - - Z Separator - Zl Line separator - Zp Paragraph separator - Zs Space separator -- -
-
- Xan Alphanumeric: union of properties L and N - Xps POSIX space: property Z or tab, NL, VT, FF, CR - Xsp Perl space: property Z or tab, NL, VT, FF, CR - Xuc Univerally-named character: one that can be - represented by a Universal Character Name - Xwd Perl word: property Xan or underscore --Perl and POSIX space are now the same. Perl added VT to its space character set -at release 5.18 and PCRE changed at release 8.34. - -
-Arabic, -Armenian, -Avestan, -Balinese, -Bamum, -Bassa_Vah, -Batak, -Bengali, -Bopomofo, -Brahmi, -Braille, -Buginese, -Buhid, -Canadian_Aboriginal, -Carian, -Caucasian_Albanian, -Chakma, -Cham, -Cherokee, -Common, -Coptic, -Cuneiform, -Cypriot, -Cyrillic, -Deseret, -Devanagari, -Duployan, -Egyptian_Hieroglyphs, -Elbasan, -Ethiopic, -Georgian, -Glagolitic, -Gothic, -Grantha, -Greek, -Gujarati, -Gurmukhi, -Han, -Hangul, -Hanunoo, -Hebrew, -Hiragana, -Imperial_Aramaic, -Inherited, -Inscriptional_Pahlavi, -Inscriptional_Parthian, -Javanese, -Kaithi, -Kannada, -Katakana, -Kayah_Li, -Kharoshthi, -Khmer, -Khojki, -Khudawadi, -Lao, -Latin, -Lepcha, -Limbu, -Linear_A, -Linear_B, -Lisu, -Lycian, -Lydian, -Mahajani, -Malayalam, -Mandaic, -Manichaean, -Meetei_Mayek, -Mende_Kikakui, -Meroitic_Cursive, -Meroitic_Hieroglyphs, -Miao, -Modi, -Mongolian, -Mro, -Myanmar, -Nabataean, -New_Tai_Lue, -Nko, -Ogham, -Ol_Chiki, -Old_Italic, -Old_North_Arabian, -Old_Permic, -Old_Persian, -Old_South_Arabian, -Old_Turkic, -Oriya, -Osmanya, -Pahawh_Hmong, -Palmyrene, -Pau_Cin_Hau, -Phags_Pa, -Phoenician, -Psalter_Pahlavi, -Rejang, -Runic, -Samaritan, -Saurashtra, -Sharada, -Shavian, -Siddham, -Sinhala, -Sora_Sompeng, -Sundanese, -Syloti_Nagri, -Syriac, -Tagalog, -Tagbanwa, -Tai_Le, -Tai_Tham, -Tai_Viet, -Takri, -Tamil, -Telugu, -Thaana, -Thai, -Tibetan, -Tifinagh, -Tirhuta, -Ugaritic, -Vai, -Warang_Citi, -Yi. -
--
- [...] positive character class - [^...] negative character class - [x-y] range (can be used for hex characters) - [[:xxx:]] positive POSIX named set - [[:^xxx:]] negative POSIX named set - - alnum alphanumeric - alpha alphabetic - ascii 0-127 - blank space or tab - cntrl control character - digit decimal digit - graph printing, excluding space - lower lower case letter - print printing, including space - punct printing, excluding alphanumeric - space white space - upper upper case letter - word same as \w - xdigit hexadecimal digit --In PCRE, POSIX character set names recognize only ASCII characters by default, -but some of them use Unicode properties if PCRE_UCP is set. You can use -\Q...\E inside a character class. - -
-
- ? 0 or 1, greedy - ?+ 0 or 1, possessive - ?? 0 or 1, lazy - * 0 or more, greedy - *+ 0 or more, possessive - *? 0 or more, lazy - + 1 or more, greedy - ++ 1 or more, possessive - +? 1 or more, lazy - {n} exactly n - {n,m} at least n, no more than m, greedy - {n,m}+ at least n, no more than m, possessive - {n,m}? at least n, no more than m, lazy - {n,} n or more, greedy - {n,}+ n or more, possessive - {n,}? n or more, lazy -- -
-
- \b word boundary - \B not a word boundary - ^ start of subject - also after internal newline in multiline mode - \A start of subject - $ end of subject - also before newline at end of subject - also before internal newline in multiline mode - \Z end of subject - also before newline at end of subject - \z end of subject - \G first matching position in subject -- -
-
- \K reset start of match --\K is honoured in positive assertions, but ignored in negative ones. - -
-
- expr|expr|expr... -- -
-
- (...) capturing group - (?<name>...) named capturing group (Perl) - (?'name'...) named capturing group (Perl) - (?P<name>...) named capturing group (Python) - (?:...) non-capturing group - (?|...) non-capturing group; reset group numbers for - capturing groups in each alternative -- -
-
- (?>...) atomic, non-capturing group -- -
-
- (?#....) comment (not nestable) -- -
-
- (?i) caseless - (?J) allow duplicate names - (?m) multiline - (?s) single line (dotall) - (?U) default ungreedy (lazy) - (?x) extended (ignore white space) - (?-...) unset option(s) --The following are recognized only at the very start of a pattern or after one -of the newline or \R options with similar syntax. More than one of them may -appear. -
- (*LIMIT_MATCH=d) set the match limit to d (decimal number) - (*LIMIT_RECURSION=d) set the recursion limit to d (decimal number) - (*NO_AUTO_POSSESS) no auto-possessification (PCRE_NO_AUTO_POSSESS) - (*NO_START_OPT) no start-match optimization (PCRE_NO_START_OPTIMIZE) - (*UTF8) set UTF-8 mode: 8-bit library (PCRE_UTF8) - (*UTF16) set UTF-16 mode: 16-bit library (PCRE_UTF16) - (*UTF32) set UTF-32 mode: 32-bit library (PCRE_UTF32) - (*UTF) set appropriate UTF mode for the library in use - (*UCP) set PCRE_UCP (use Unicode properties for \d etc) --Note that LIMIT_MATCH and LIMIT_RECURSION can only reduce the value of the -limits set by the caller of pcre_exec(), not increase them. - -
-These are recognized only at the very start of the pattern or after option -settings with a similar syntax. -
- (*CR) carriage return only - (*LF) linefeed only - (*CRLF) carriage return followed by linefeed - (*ANYCRLF) all three of the above - (*ANY) any Unicode newline sequence -- -
-These are recognized only at the very start of the pattern or after option -setting with a similar syntax. -
- (*BSR_ANYCRLF) CR, LF, or CRLF - (*BSR_UNICODE) any Unicode newline sequence -- -
-
- (?=...) positive look ahead - (?!...) negative look ahead - (?<=...) positive look behind - (?<!...) negative look behind --Each top-level branch of a look behind must be of a fixed length. - -
-
- \n reference by number (can be ambiguous) - \gn reference by number - \g{n} reference by number - \g{-n} relative reference by number - \k<name> reference by name (Perl) - \k'name' reference by name (Perl) - \g{name} reference by name (Perl) - \k{name} reference by name (.NET) - (?P=name) reference by name (Python) -- -
-
- (?R) recurse whole pattern - (?n) call subpattern by absolute number - (?+n) call subpattern by relative number - (?-n) call subpattern by relative number - (?&name) call subpattern by name (Perl) - (?P>name) call subpattern by name (Python) - \g<name> call subpattern by name (Oniguruma) - \g'name' call subpattern by name (Oniguruma) - \g<n> call subpattern by absolute number (Oniguruma) - \g'n' call subpattern by absolute number (Oniguruma) - \g<+n> call subpattern by relative number (PCRE extension) - \g'+n' call subpattern by relative number (PCRE extension) - \g<-n> call subpattern by relative number (PCRE extension) - \g'-n' call subpattern by relative number (PCRE extension) -- -
-
- (?(condition)yes-pattern) - (?(condition)yes-pattern|no-pattern) - - (?(n)... absolute reference condition - (?(+n)... relative reference condition - (?(-n)... relative reference condition - (?(<name>)... named reference condition (Perl) - (?('name')... named reference condition (Perl) - (?(name)... named reference condition (PCRE) - (?(R)... overall recursion condition - (?(Rn)... specific group recursion condition - (?(R&name)... specific recursion condition - (?(DEFINE)... define subpattern for reference - (?(assert)... assertion condition -- -
-The following act immediately they are reached: -
- (*ACCEPT) force successful match - (*FAIL) force backtrack; synonym (*F) - (*MARK:NAME) set name to be passed back; synonym (*:NAME) --The following act only when a subsequent match failure causes a backtrack to -reach them. They all force a match failure, but they differ in what happens -afterwards. Those that advance the start-of-match point do so only if the -pattern is not anchored. -
- (*COMMIT) overall failure, no advance of starting point - (*PRUNE) advance to next starting character - (*PRUNE:NAME) equivalent to (*MARK:NAME)(*PRUNE) - (*SKIP) advance to current matching position - (*SKIP:NAME) advance to position corresponding to an earlier - (*MARK:NAME); if not found, the (*SKIP) is ignored - (*THEN) local failure, backtrack to next alternation - (*THEN:NAME) equivalent to (*MARK:NAME)(*THEN) -- -
-
- (?C) callout - (?Cn) callout with data n -- -
-pcrepattern(3), pcreapi(3), pcrecallout(3), -pcrematching(3), pcre(3). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 08 January 2014
-
-Copyright © 1997-2014 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcretest.html b/libs/Pcre16/docs/doc/html/pcretest.html deleted file mode 100644 index ba540d3c38..0000000000 --- a/libs/Pcre16/docs/doc/html/pcretest.html +++ /dev/null @@ -1,1163 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-pcretest [options] [input file [output file]]
-
-
-pcretest was written as a test program for the PCRE regular expression
-library itself, but it can also be used for experimenting with regular
-expressions. This document describes the features of the test program; for
-details of the regular expressions themselves, see the
-pcrepattern
-documentation. For details of the PCRE library function calls and their
-options, see the
-pcreapi
-,
-pcre16
-and
-pcre32
-documentation.
-
-The input for pcretest is a sequence of regular expression patterns and -strings to be matched, as described below. The output shows the result of each -match. Options on the command line and the patterns control PCRE options and -exactly what is output. -
--As PCRE has evolved, it has acquired many different features, and as a result, -pcretest now has rather a lot of obscure options for testing every -possible feature. Some of these options are specifically designed for use in -conjunction with the test script and data files that are distributed as part of -PCRE, and are unlikely to be of use otherwise. They are all documented here, -but without much justification. -
--Input to pcretest is processed line by line, either by calling the C -library's fgets() function, or via the libreadline library (see -below). In Unix-like environments, fgets() treats any bytes other than -newline as data characters. However, in some Windows environments character 26 -(hex 1A) causes an immediate end of file, and no further data is read. For -maximum portability, therefore, it is safest to use only ASCII characters in -pcretest input files. -
--The input is processed using using C's string functions, so must not -contain binary zeroes, even though in Unix-like environments, fgets() -treats any bytes other than newline as data characters. -
--From release 8.30, two separate PCRE libraries can be built. The original one -supports 8-bit character strings, whereas the newer 16-bit library supports -character strings encoded in 16-bit units. From release 8.32, a third library -can be built, supporting character strings encoded in 32-bit units. The -pcretest program can be used to test all three libraries. However, it is -itself still an 8-bit program, reading 8-bit input and writing 8-bit output. -When testing the 16-bit or 32-bit library, the patterns and data strings are -converted to 16- or 32-bit format before being passed to the PCRE library -functions. Results are converted to 8-bit for output. -
--References to functions and structures of the form pcre[16|32]_xx below -mean "pcre_xx when using the 8-bit library, pcre16_xx when using -the 16-bit library, or pcre32_xx when using the 32-bit library". -
---8 -If both the 8-bit library has been built, this option causes the 8-bit library -to be used (which is the default); if the 8-bit library has not been built, -this option causes an error. -
---16 -If both the 8-bit or the 32-bit, and the 16-bit libraries have been built, this -option causes the 16-bit library to be used. If only the 16-bit library has been -built, this is the default (so has no effect). If only the 8-bit or the 32-bit -library has been built, this option causes an error. -
---32 -If both the 8-bit or the 16-bit, and the 32-bit libraries have been built, this -option causes the 32-bit library to be used. If only the 32-bit library has been -built, this is the default (so has no effect). If only the 8-bit or the 16-bit -library has been built, this option causes an error. -
---b -Behave as if each pattern has the /B (show byte code) modifier; the -internal form is output after compilation. -
---C -Output the version number of the PCRE library, and all available information -about the optional features that are included, and then exit with zero exit -code. All other options are ignored. -
---C option -Output information about a specific build-time option, then exit. This -functionality is intended for use in scripts such as RunTest. The -following options output the value and set the exit code as indicated: -
- ebcdic-nl the code for LF (= NL) in an EBCDIC environment: - 0x15 or 0x25 - 0 if used in an ASCII environment - exit code is always 0 - linksize the configured internal link size (2, 3, or 4) - exit code is set to the link size - newline the default newline setting: - CR, LF, CRLF, ANYCRLF, or ANY - exit code is always 0 - bsr the default setting for what \R matches: - ANYCRLF or ANY - exit code is always 0 --The following options output 1 for true or 0 for false, and set the exit code -to the same value: -
- ebcdic compiled for an EBCDIC environment - jit just-in-time support is available - pcre16 the 16-bit library was built - pcre32 the 32-bit library was built - pcre8 the 8-bit library was built - ucp Unicode property support is available - utf UTF-8 and/or UTF-16 and/or UTF-32 support - is available --If an unknown option is given, an error message is output; the exit code is 0. - -
--d -Behave as if each pattern has the /D (debug) modifier; the internal -form and information about the compiled pattern is output after compilation; --d is equivalent to -b -i. -
---dfa -Behave as if each data line contains the \D escape sequence; this causes the -alternative matching function, pcre[16|32]_dfa_exec(), to be used instead -of the standard pcre[16|32]_exec() function (more detail is given below). -
---help -Output a brief summary these options and then exit. -
---i -Behave as if each pattern has the /I modifier; information about the -compiled pattern is given after compilation. -
---M -Behave as if each data line contains the \M escape sequence; this causes -PCRE to discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings by -calling pcre[16|32]_exec() repeatedly with different limits. -
---m -Output the size of each compiled pattern after it has been compiled. This is -equivalent to adding /M to each regular expression. The size is given in -bytes for both libraries. -
---O -Behave as if each pattern has the /O modifier, that is disable -auto-possessification for all patterns. -
---o osize -Set the number of elements in the output vector that is used when calling -pcre[16|32]_exec() or pcre[16|32]_dfa_exec() to be osize. The -default value is 45, which is enough for 14 capturing subexpressions for -pcre[16|32]_exec() or 22 different matches for -pcre[16|32]_dfa_exec(). -The vector size can be changed for individual matching calls by including \O -in the data line (see below). -
---p -Behave as if each pattern has the /P modifier; the POSIX wrapper API is -used to call PCRE. None of the other options has any effect when -p is -set. This option can be used only with the 8-bit library. -
---q -Do not output the version number of pcretest at the start of execution. -
---S size -On Unix-like systems, set the size of the run-time stack to size -megabytes. -
---s or -s+ -Behave as if each pattern has the /S modifier; in other words, force each -pattern to be studied. If -s+ is used, all the JIT compile options are -passed to pcre[16|32]_study(), causing just-in-time optimization to be set -up if it is available, for both full and partial matching. Specific JIT compile -options can be selected by following -s+ with a digit in the range 1 to -7, which selects the JIT compile modes as follows: -
- 1 normal match only - 2 soft partial match only - 3 normal match and soft partial match - 4 hard partial match only - 6 soft and hard partial match - 7 all three modes (default) --If -s++ is used instead of -s+ (with or without a following digit), -the text "(JIT)" is added to the first output line after a match or no match -when JIT-compiled code was actually used. -
--t -Run each compile, study, and match many times with a timer, and output the -resulting times per compile, study, or match (in milliseconds). Do not set --m with -t, because you will then get the size output a zillion -times, and the timing will be distorted. You can control the number of -iterations that are used for timing by following -t with a number (as a -separate item on the command line). For example, "-t 1000" iterates 1000 times. -The default is to iterate 500000 times. -
---tm -This is like -t except that it times only the matching phase, not the -compile or study phases. -
---T -TM -These behave like -t and -tm, but in addition, at the end of a run, -the total times for all compiles, studies, and matches are output. -
--If pcretest is given two filename arguments, it reads from the first and -writes to the second. If it is given only one filename argument, it reads from -that file and writes to stdout. Otherwise, it reads from stdin and writes to -stdout, and prompts for each line of input, using "re>" to prompt for regular -expressions, and "data>" to prompt for data lines. -
--When pcretest is built, a configuration option can specify that it should -be linked with the libreadline library. When this is done, if the input -is from a terminal, it is read using the readline() function. This -provides line-editing and history facilities. The output from the -help -option states whether or not readline() will be used. -
--The program handles any number of sets of input on a single input file. Each -set starts with a regular expression, and continues with any number of data -lines to be matched against that pattern. -
--Each data line is matched separately and independently. If you want to do -multi-line matches, you have to use the \n escape sequence (or \r or \r\n, -etc., depending on the newline setting) in a single line of input to encode the -newline sequences. There is no limit on the length of data lines; the input -buffer is automatically extended if it is too small. -
--An empty line signals the end of the data lines, at which point a new regular -expression is read. The regular expressions are given enclosed in any -non-alphanumeric delimiters other than backslash, for example: -
- /(a|bc)x+yz/ --White space before the initial delimiter is ignored. A regular expression may -be continued over several input lines, in which case the newline characters are -included within it. It is possible to include the delimiter within the pattern -by escaping it, for example -
- /abc\/def/ --If you do so, the escape and the delimiter form part of the pattern, but since -delimiters are always non-alphanumeric, this does not affect its interpretation. -If the terminating delimiter is immediately followed by a backslash, for -example, -
- /abc/\ --then a backslash is added to the end of the pattern. This is done to provide a -way of testing the error condition that arises if a pattern finishes with a -backslash, because -
- /abc\/ --is interpreted as the first line of a pattern that starts with "abc/", causing -pcretest to read the next line as a continuation of the regular expression. - -
-A pattern may be followed by any number of modifiers, which are mostly single -characters, though some of these can be qualified by further characters. -Following Perl usage, these are referred to below as, for example, "the -/i modifier", even though the delimiter of the pattern need not always be -a slash, and no slash is used when writing modifiers. White space may appear -between the final pattern delimiter and the first modifier, and between the -modifiers themselves. For reference, here is a complete list of modifiers. They -fall into several groups that are described in detail in the following -sections. -
- /8 set UTF mode - /9 set PCRE_NEVER_UTF (locks out UTF mode) - /? disable UTF validity check - /+ show remainder of subject after match - /= show all captures (not just those that are set) - - /A set PCRE_ANCHORED - /B show compiled code - /C set PCRE_AUTO_CALLOUT - /D same as /B plus /I - /E set PCRE_DOLLAR_ENDONLY - /F flip byte order in compiled pattern - /f set PCRE_FIRSTLINE - /G find all matches (shorten string) - /g find all matches (use startoffset) - /I show information about pattern - /i set PCRE_CASELESS - /J set PCRE_DUPNAMES - /K show backtracking control names - /L set locale - /M show compiled memory size - /m set PCRE_MULTILINE - /N set PCRE_NO_AUTO_CAPTURE - /O set PCRE_NO_AUTO_POSSESS - /P use the POSIX wrapper - /Q test external stack check function - /S study the pattern after compilation - /s set PCRE_DOTALL - /T select character tables - /U set PCRE_UNGREEDY - /W set PCRE_UCP - /X set PCRE_EXTRA - /x set PCRE_EXTENDED - /Y set PCRE_NO_START_OPTIMIZE - /Z don't show lengths in /B output - - /<any> set PCRE_NEWLINE_ANY - /<anycrlf> set PCRE_NEWLINE_ANYCRLF - /<cr> set PCRE_NEWLINE_CR - /<crlf> set PCRE_NEWLINE_CRLF - /<lf> set PCRE_NEWLINE_LF - /<bsr_anycrlf> set PCRE_BSR_ANYCRLF - /<bsr_unicode> set PCRE_BSR_UNICODE - /<JS> set PCRE_JAVASCRIPT_COMPAT - -- -
-The /i, /m, /s, and /x modifiers set the PCRE_CASELESS, -PCRE_MULTILINE, PCRE_DOTALL, or PCRE_EXTENDED options, respectively, when -pcre[16|32]_compile() is called. These four modifier letters have the same -effect as they do in Perl. For example: -
- /caseless/i - -- -
-The following table shows additional modifiers for setting PCRE compile-time -options that do not correspond to anything in Perl: -
- /8 PCRE_UTF8 ) when using the 8-bit - /? PCRE_NO_UTF8_CHECK ) library - - /8 PCRE_UTF16 ) when using the 16-bit - /? PCRE_NO_UTF16_CHECK ) library - - /8 PCRE_UTF32 ) when using the 32-bit - /? PCRE_NO_UTF32_CHECK ) library - - /9 PCRE_NEVER_UTF - /A PCRE_ANCHORED - /C PCRE_AUTO_CALLOUT - /E PCRE_DOLLAR_ENDONLY - /f PCRE_FIRSTLINE - /J PCRE_DUPNAMES - /N PCRE_NO_AUTO_CAPTURE - /O PCRE_NO_AUTO_POSSESS - /U PCRE_UNGREEDY - /W PCRE_UCP - /X PCRE_EXTRA - /Y PCRE_NO_START_OPTIMIZE - /<any> PCRE_NEWLINE_ANY - /<anycrlf> PCRE_NEWLINE_ANYCRLF - /<cr> PCRE_NEWLINE_CR - /<crlf> PCRE_NEWLINE_CRLF - /<lf> PCRE_NEWLINE_LF - /<bsr_anycrlf> PCRE_BSR_ANYCRLF - /<bsr_unicode> PCRE_BSR_UNICODE - /<JS> PCRE_JAVASCRIPT_COMPAT --The modifiers that are enclosed in angle brackets are literal strings as shown, -including the angle brackets, but the letters within can be in either case. -This example sets multiline matching with CRLF as the line ending sequence: -
- /^abc/m<CRLF> --As well as turning on the PCRE_UTF8/16/32 option, the /8 modifier causes -all non-printing characters in output strings to be printed using the -\x{hh...} notation. Otherwise, those less than 0x100 are output in hex without -the curly brackets. - -
-Full details of the PCRE options are given in the -pcreapi -documentation. -
--Searching for all possible matches within each subject string can be requested -by the /g or /G modifier. After finding a match, PCRE is called -again to search the remainder of the subject string. The difference between -/g and /G is that the former uses the startoffset argument to -pcre[16|32]_exec() to start searching at a new point within the entire -string (which is in effect what Perl does), whereas the latter passes over a -shortened substring. This makes a difference to the matching process if the -pattern begins with a lookbehind assertion (including \b or \B). -
--If any call to pcre[16|32]_exec() in a /g or /G sequence matches -an empty string, the next call is done with the PCRE_NOTEMPTY_ATSTART and -PCRE_ANCHORED flags set in order to search for another, non-empty, match at the -same point. If this second match fails, the start offset is advanced, and the -normal match is retried. This imitates the way Perl handles such cases when -using the /g modifier or the split() function. Normally, the start -offset is advanced by one character, but if the newline convention recognizes -CRLF as a newline, and the current character is CR followed by LF, an advance -of two is used. -
--There are yet more modifiers for controlling the way pcretest -operates. -
--The /+ modifier requests that as well as outputting the substring that -matched the entire pattern, pcretest should in addition output the -remainder of the subject string. This is useful for tests where the subject -contains multiple copies of the same substring. If the + modifier appears -twice, the same action is taken for captured substrings. In each case the -remainder is output on the following line with a plus character following the -capture number. Note that this modifier must not immediately follow the /S -modifier because /S+ and /S++ have other meanings. -
--The /= modifier requests that the values of all potential captured -parentheses be output after a match. By default, only those up to the highest -one actually used in the match are output (corresponding to the return code -from pcre[16|32]_exec()). Values in the offsets vector corresponding to -higher numbers should be set to -1, and these are output as "<unset>". This -modifier gives a way of checking that this is happening. -
--The /B modifier is a debugging feature. It requests that pcretest -output a representation of the compiled code after compilation. Normally this -information contains length and offset values; however, if /Z is also -present, this data is replaced by spaces. This is a special feature for use in -the automatic test scripts; it ensures that the same output is generated for -different internal link sizes. -
--The /D modifier is a PCRE debugging feature, and is equivalent to -/BI, that is, both the /B and the /I modifiers. -
--The /F modifier causes pcretest to flip the byte order of the -2-byte and 4-byte fields in the compiled pattern. This facility is for testing -the feature in PCRE that allows it to execute patterns that were compiled on a -host with a different endianness. This feature is not available when the POSIX -interface to PCRE is being used, that is, when the /P pattern modifier is -specified. See also the section about saving and reloading compiled patterns -below. -
--The /I modifier requests that pcretest output information about the -compiled pattern (whether it is anchored, has a fixed first character, and -so on). It does this by calling pcre[16|32]_fullinfo() after compiling a -pattern. If the pattern is studied, the results of that are also output. In -this output, the word "char" means a non-UTF character, that is, the value of a -single data item (8-bit, 16-bit, or 32-bit, depending on the library that is -being tested). -
--The /K modifier requests pcretest to show names from backtracking -control verbs that are returned from calls to pcre[16|32]_exec(). It causes -pcretest to create a pcre[16|32]_extra block if one has not already -been created by a call to pcre[16|32]_study(), and to set the -PCRE_EXTRA_MARK flag and the mark field within it, every time that -pcre[16|32]_exec() is called. If the variable that the mark field -points to is non-NULL for a match, non-match, or partial match, pcretest -prints the string to which it points. For a match, this is shown on a line by -itself, tagged with "MK:". For a non-match it is added to the message. -
--The /L modifier must be followed directly by the name of a locale, for -example, -
- /pattern/Lfr_FR --For this reason, it must be the last modifier. The given locale is set, -pcre[16|32]_maketables() is called to build a set of character tables for -the locale, and this is then passed to pcre[16|32]_compile() when compiling -the regular expression. Without an /L (or /T) modifier, NULL is -passed as the tables pointer; that is, /L applies only to the expression -on which it appears. - -
-The /M modifier causes the size in bytes of the memory block used to hold -the compiled pattern to be output. This does not include the size of the -pcre[16|32] block; it is just the actual compiled data. If the pattern is -successfully studied with the PCRE_STUDY_JIT_COMPILE option, the size of the -JIT compiled code is also output. -
--The /Q modifier is used to test the use of pcre_stack_guard. It -must be followed by '0' or '1', specifying the return code to be given from an -external function that is passed to PCRE and used for stack checking during -compilation (see the -pcreapi -documentation for details). -
--The /S modifier causes pcre[16|32]_study() to be called after the -expression has been compiled, and the results used when the expression is -matched. There are a number of qualifying characters that may follow /S. -They may appear in any order. -
--If /S is followed by an exclamation mark, pcre[16|32]_study() is -called with the PCRE_STUDY_EXTRA_NEEDED option, causing it always to return a -pcre_extra block, even when studying discovers no useful information. -
--If /S is followed by a second S character, it suppresses studying, even -if it was requested externally by the -s command line option. This makes -it possible to specify that certain patterns are always studied, and others are -never studied, independently of -s. This feature is used in the test -files in a few cases where the output is different when the pattern is studied. -
--If the /S modifier is followed by a + character, the call to -pcre[16|32]_study() is made with all the JIT study options, requesting -just-in-time optimization support if it is available, for both normal and -partial matching. If you want to restrict the JIT compiling modes, you can -follow /S+ with a digit in the range 1 to 7: -
- 1 normal match only - 2 soft partial match only - 3 normal match and soft partial match - 4 hard partial match only - 6 soft and hard partial match - 7 all three modes (default) --If /S++ is used instead of /S+ (with or without a following digit), -the text "(JIT)" is added to the first output line after a match or no match -when JIT-compiled code was actually used. - -
-Note that there is also an independent /+ modifier; it must not be given -immediately after /S or /S+ because this will be misinterpreted. -
--If JIT studying is successful, the compiled JIT code will automatically be used -when pcre[16|32]_exec() is run, except when incompatible run-time options -are specified. For more details, see the -pcrejit -documentation. See also the \J escape sequence below for a way of -setting the size of the JIT stack. -
--Finally, if /S is followed by a minus character, JIT compilation is -suppressed, even if it was requested externally by the -s command line -option. This makes it possible to specify that JIT is never to be used for -certain patterns. -
--The /T modifier must be followed by a single digit. It causes a specific -set of built-in character tables to be passed to pcre[16|32]_compile(). It -is used in the standard PCRE tests to check behaviour with different character -tables. The digit specifies the tables as follows: -
- 0 the default ASCII tables, as distributed in - pcre_chartables.c.dist - 1 a set of tables defining ISO 8859 characters --In table 1, some characters whose codes are greater than 128 are identified as -letters, digits, spaces, etc. - -
-The /P modifier causes pcretest to call PCRE via the POSIX wrapper -API rather than its native API. This supports only the 8-bit library. When -/P is set, the following modifiers set options for the regcomp() -function: -
- /i REG_ICASE - /m REG_NEWLINE - /N REG_NOSUB - /s REG_DOTALL ) - /U REG_UNGREEDY ) These options are not part of - /W REG_UCP ) the POSIX standard - /8 REG_UTF8 ) --The /+ modifier works as described above. All other modifiers are -ignored. - -
-PCRE can be compiled with or without support for certain features such as -UTF-8/16/32 or Unicode properties. Accordingly, the standard tests are split up -into a number of different files that are selected for running depending on -which features are available. When updating the tests, it is all too easy to -put a new test into the wrong file by mistake; for example, to put a test that -requires UTF support into a file that is used when it is not available. To help -detect such mistakes as early as possible, there is a facility for locking out -specific modifiers. If an input line for pcretest starts with the string -"< forbid " the following sequence of characters is taken as a list of -forbidden modifiers. For example, in the test files that must not use UTF or -Unicode property support, this line appears: -
- < forbid 8W --This locks out the /8 and /W modifiers. An immediate error is given if they are -subsequently encountered. If the character string contains < but not >, all the -multi-character modifiers that begin with < are locked out. Otherwise, such -modifiers must be explicitly listed, for example: -
- < forbid <JS><cr> --There must be a single space between < and "forbid" for this feature to be -recognised. If there is not, the line is interpreted either as a request to -re-load a pre-compiled pattern (see "SAVING AND RELOADING COMPILED PATTERNS" -below) or, if there is a another < character, as a pattern that uses < as its -delimiter. - -
-Before each data line is passed to pcre[16|32]_exec(), leading and trailing -white space is removed, and it is then scanned for \ escapes. Some of these -are pretty esoteric features, intended for checking out some of the more -complicated features of PCRE. If you are just testing "ordinary" regular -expressions, you probably don't need any of these. The following escapes are -recognized: -
- \a alarm (BEL, \x07) - \b backspace (\x08) - \e escape (\x27) - \f form feed (\x0c) - \n newline (\x0a) - \qdd set the PCRE_MATCH_LIMIT limit to dd (any number of digits) - \r carriage return (\x0d) - \t tab (\x09) - \v vertical tab (\x0b) - \nnn octal character (up to 3 octal digits); always - a byte unless > 255 in UTF-8 or 16-bit or 32-bit mode - \o{dd...} octal character (any number of octal digits} - \xhh hexadecimal byte (up to 2 hex digits) - \x{hh...} hexadecimal character (any number of hex digits) - \A pass the PCRE_ANCHORED option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \B pass the PCRE_NOTBOL option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \Cdd call pcre[16|32]_copy_substring() for substring dd after a successful match (number less than 32) - \Cname call pcre[16|32]_copy_named_substring() for substring "name" after a successful match (name termin- - ated by next non alphanumeric character) - \C+ show the current captured substrings at callout time - \C- do not supply a callout function - \C!n return 1 instead of 0 when callout number n is reached - \C!n!m return 1 instead of 0 when callout number n is reached for the nth time - \C*n pass the number n (may be negative) as callout data; this is used as the callout return value - \D use the pcre[16|32]_dfa_exec() match function - \F only shortest match for pcre[16|32]_dfa_exec() - \Gdd call pcre[16|32]_get_substring() for substring dd after a successful match (number less than 32) - \Gname call pcre[16|32]_get_named_substring() for substring "name" after a successful match (name termin- - ated by next non-alphanumeric character) - \Jdd set up a JIT stack of dd kilobytes maximum (any number of digits) - \L call pcre[16|32]_get_substringlist() after a successful match - \M discover the minimum MATCH_LIMIT and MATCH_LIMIT_RECURSION settings - \N pass the PCRE_NOTEMPTY option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec(); if used twice, pass the - PCRE_NOTEMPTY_ATSTART option - \Odd set the size of the output vector passed to pcre[16|32]_exec() to dd (any number of digits) - \P pass the PCRE_PARTIAL_SOFT option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec(); if used twice, pass the - PCRE_PARTIAL_HARD option - \Qdd set the PCRE_MATCH_LIMIT_RECURSION limit to dd (any number of digits) - \R pass the PCRE_DFA_RESTART option to pcre[16|32]_dfa_exec() - \S output details of memory get/free calls during matching - \Y pass the PCRE_NO_START_OPTIMIZE option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \Z pass the PCRE_NOTEOL option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \? pass the PCRE_NO_UTF[8|16|32]_CHECK option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \>dd start the match at offset dd (optional "-"; then any number of digits); this sets the startoffset - argument for pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \<cr> pass the PCRE_NEWLINE_CR option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \<lf> pass the PCRE_NEWLINE_LF option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \<crlf> pass the PCRE_NEWLINE_CRLF option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \<anycrlf> pass the PCRE_NEWLINE_ANYCRLF option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() - \<any> pass the PCRE_NEWLINE_ANY option to pcre[16|32]_exec() or pcre[16|32]_dfa_exec() --The use of \x{hh...} is not dependent on the use of the /8 modifier on -the pattern. It is recognized always. There may be any number of hexadecimal -digits inside the braces; invalid values provoke error messages. - -
-Note that \xhh specifies one byte rather than one character in UTF-8 mode; -this makes it possible to construct invalid UTF-8 sequences for testing -purposes. On the other hand, \x{hh} is interpreted as a UTF-8 character in -UTF-8 mode, generating more than one byte if the value is greater than 127. -When testing the 8-bit library not in UTF-8 mode, \x{hh} generates one byte -for values less than 256, and causes an error for greater values. -
--In UTF-16 mode, all 4-digit \x{hhhh} values are accepted. This makes it -possible to construct invalid UTF-16 sequences for testing purposes. -
--In UTF-32 mode, all 4- to 8-digit \x{...} values are accepted. This makes it -possible to construct invalid UTF-32 sequences for testing purposes. -
--The escapes that specify line ending sequences are literal strings, exactly as -shown. No more than one newline setting should be present in any data line. -
--A backslash followed by anything else just escapes the anything else. If -the very last character is a backslash, it is ignored. This gives a way of -passing an empty line as data, since a real empty line terminates the data -input. -
--The \J escape provides a way of setting the maximum stack size that is -used by the just-in-time optimization code. It is ignored if JIT optimization -is not being used. Providing a stack that is larger than the default 32K is -necessary only for very complicated patterns. -
--If \M is present, pcretest calls pcre[16|32]_exec() several times, -with different values in the match_limit and match_limit_recursion -fields of the pcre[16|32]_extra data structure, until it finds the minimum -numbers for each parameter that allow pcre[16|32]_exec() to complete without -error. Because this is testing a specific feature of the normal interpretive -pcre[16|32]_exec() execution, the use of any JIT optimization that might -have been set up by the /S+ qualifier of -s+ option is disabled. -
--The match_limit number is a measure of the amount of backtracking -that takes place, and checking it out can be instructive. For most simple -matches, the number is quite small, but for patterns with very large numbers of -matching possibilities, it can become large very quickly with increasing length -of subject string. The match_limit_recursion number is a measure of how -much stack (or, if PCRE is compiled with NO_RECURSE, how much heap) memory is -needed to complete the match attempt. -
--When \O is used, the value specified may be higher or lower than the size set -by the -O command line option (or defaulted to 45); \O applies only to -the call of pcre[16|32]_exec() for the line in which it appears. -
--If the /P modifier was present on the pattern, causing the POSIX wrapper -API to be used, the only option-setting sequences that have any effect are \B, -\N, and \Z, causing REG_NOTBOL, REG_NOTEMPTY, and REG_NOTEOL, respectively, -to be passed to regexec(). -
--By default, pcretest uses the standard PCRE matching function, -pcre[16|32]_exec() to match each data line. PCRE also supports an -alternative matching function, pcre[16|32]_dfa_test(), which operates in a -different way, and has some restrictions. The differences between the two -functions are described in the -pcrematching -documentation. -
--If a data line contains the \D escape sequence, or if the command line -contains the -dfa option, the alternative matching function is used. -This function finds all possible matches at a given point. If, however, the \F -escape sequence is present in the data line, it stops after the first match is -found. This is always the shortest possible match. -
--This section describes the output when the normal matching function, -pcre[16|32]_exec(), is being used. -
--When a match succeeds, pcretest outputs the list of captured substrings -that pcre[16|32]_exec() returns, starting with number 0 for the string that -matched the whole pattern. Otherwise, it outputs "No match" when the return is -PCRE_ERROR_NOMATCH, and "Partial match:" followed by the partially matching -substring when pcre[16|32]_exec() returns PCRE_ERROR_PARTIAL. (Note that -this is the entire substring that was inspected during the partial match; it -may include characters before the actual match start if a lookbehind assertion, -\K, \b, or \B was involved.) For any other return, pcretest outputs -the PCRE negative error number and a short descriptive phrase. If the error is -a failed UTF string check, the offset of the start of the failing character and -the reason code are also output, provided that the size of the output vector is -at least two. Here is an example of an interactive pcretest run. -
- $ pcretest - PCRE version 8.13 2011-04-30 - - re> /^abc(\d+)/ - data> abc123 - 0: abc123 - 1: 123 - data> xyz - No match --Unset capturing substrings that are not followed by one that is set are not -returned by pcre[16|32]_exec(), and are not shown by pcretest. In the -following example, there are two capturing substrings, but when the first data -line is matched, the second, unset substring is not shown. An "internal" unset -substring is shown as "<unset>", as for the second data line. -
- re> /(a)|(b)/ - data> a - 0: a - 1: a - data> b - 0: b - 1: <unset> - 2: b --If the strings contain any non-printing characters, they are output as \xhh -escapes if the value is less than 256 and UTF mode is not set. Otherwise they -are output as \x{hh...} escapes. See below for the definition of non-printing -characters. If the pattern has the /+ modifier, the output for substring -0 is followed by the the rest of the subject string, identified by "0+" like -this: -
- re> /cat/+ - data> cataract - 0: cat - 0+ aract --If the pattern has the /g or /G modifier, the results of successive -matching attempts are output in sequence, like this: -
- re> /\Bi(\w\w)/g - data> Mississippi - 0: iss - 1: ss - 0: iss - 1: ss - 0: ipp - 1: pp --"No match" is output only if the first match attempt fails. Here is an example -of a failure message (the offset 4 that is specified by \>4 is past the end of -the subject string): -
- re> /xyz/ - data> xyz\>4 - Error -24 (bad offset value) -- -
-If any of the sequences \C, \G, or \L are present in a -data line that is successfully matched, the substrings extracted by the -convenience functions are output with C, G, or L after the string number -instead of a colon. This is in addition to the normal full list. The string -length (that is, the return from the extraction function) is given in -parentheses after each string for \C and \G. -
--Note that whereas patterns can be continued over several lines (a plain ">" -prompt is used for continuations), data lines may not. However newlines can be -included in data by means of the \n escape (or \r, \r\n, etc., depending on -the newline sequence setting). -
--When the alternative matching function, pcre[16|32]_dfa_exec(), is used (by -means of the \D escape sequence or the -dfa command line option), the -output consists of a list of all the matches that start at the first point in -the subject where there is at least one match. For example: -
- re> /(tang|tangerine|tan)/ - data> yellow tangerine\D - 0: tangerine - 1: tang - 2: tan --(Using the normal matching function on this data finds only "tang".) The -longest matching string is always given first (and numbered zero). After a -PCRE_ERROR_PARTIAL return, the output is "Partial match:", followed by the -partially matching substring. (Note that this is the entire substring that was -inspected during the partial match; it may include characters before the actual -match start if a lookbehind assertion, \K, \b, or \B was involved.) - -
-If /g is present on the pattern, the search for further matches resumes -at the end of the longest match. For example: -
- re> /(tang|tangerine|tan)/g - data> yellow tangerine and tangy sultana\D - 0: tangerine - 1: tang - 2: tan - 0: tang - 1: tan - 0: tan --Since the matching function does not support substring capture, the escape -sequences that are concerned with captured substrings are not relevant. - -
-When the alternative matching function has given the PCRE_ERROR_PARTIAL return, -indicating that the subject partially matched the pattern, you can restart the -match with additional subject data by means of the \R escape sequence. For -example: -
- re> /^\d?\d(jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)\d\d$/ - data> 23ja\P\D - Partial match: 23ja - data> n05\R\D - 0: n05 --For further information about partial matching, see the -pcrepartial -documentation. - -
-If the pattern contains any callout requests, pcretest's callout function -is called during matching. This works with both matching functions. By default, -the called function displays the callout number, the start and current -positions in the text at the callout time, and the next pattern item to be -tested. For example: -
- --->pqrabcdef - 0 ^ ^ \d --This output indicates that callout number 0 occurred for a match attempt -starting at the fourth character of the subject string, when the pointer was at -the seventh character of the data, and when the next pattern item was \d. Just -one circumflex is output if the start and current positions are the same. - -
-Callouts numbered 255 are assumed to be automatic callouts, inserted as a -result of the /C pattern modifier. In this case, instead of showing the -callout number, the offset in the pattern, preceded by a plus, is output. For -example: -
- re> /\d?[A-E]\*/C - data> E* - --->E* - +0 ^ \d? - +3 ^ [A-E] - +8 ^^ \* - +10 ^ ^ - 0: E* --If a pattern contains (*MARK) items, an additional line is output whenever -a change of latest mark is passed to the callout function. For example: -
- re> /a(*MARK:X)bc/C - data> abc - --->abc - +0 ^ a - +1 ^^ (*MARK:X) - +10 ^^ b - Latest Mark: X - +11 ^ ^ c - +12 ^ ^ - 0: abc --The mark changes between matching "a" and "b", but stays the same for the rest -of the match, so nothing more is output. If, as a result of backtracking, the -mark reverts to being unset, the text "<unset>" is output. - -
-The callout function in pcretest returns zero (carry on matching) by -default, but you can use a \C item in a data line (as described above) to -change this and other parameters of the callout. -
--Inserting callouts can be helpful when using pcretest to check -complicated regular expressions. For further information about callouts, see -the -pcrecallout -documentation. -
--When pcretest is outputting text in the compiled version of a pattern, -bytes other than 32-126 are always treated as non-printing characters are are -therefore shown as hex escapes. -
--When pcretest is outputting text that is a matched part of a subject -string, it behaves in the same way, unless a different locale has been set for -the pattern (using the /L modifier). In this case, the isprint() -function to distinguish printing and non-printing characters. -
--The facilities described in this section are not available when the POSIX -interface to PCRE is being used, that is, when the /P pattern modifier is -specified. -
--When the POSIX interface is not in use, you can cause pcretest to write a -compiled pattern to a file, by following the modifiers with > and a file name. -For example: -
- /pattern/im >/some/file --See the -pcreprecompile -documentation for a discussion about saving and re-using compiled patterns. -Note that if the pattern was successfully studied with JIT optimization, the -JIT data cannot be saved. - -
-The data that is written is binary. The first eight bytes are the length of the -compiled pattern data followed by the length of the optional study data, each -written as four bytes in big-endian order (most significant byte first). If -there is no study data (either the pattern was not studied, or studying did not -return any data), the second length is zero. The lengths are followed by an -exact copy of the compiled pattern. If there is additional study data, this -(excluding any JIT data) follows immediately after the compiled pattern. After -writing the file, pcretest expects to read a new pattern. -
--A saved pattern can be reloaded into pcretest by specifying < and a file -name instead of a pattern. There must be no space between < and the file name, -which must not contain a < character, as otherwise pcretest will -interpret the line as a pattern delimited by < characters. For example: -
- re> </some/file - Compiled pattern loaded from /some/file - No study data --If the pattern was previously studied with the JIT optimization, the JIT -information cannot be saved and restored, and so is lost. When the pattern has -been loaded, pcretest proceeds to read data lines in the usual way. - -
-You can copy a file written by pcretest to a different host and reload it -there, even if the new host has opposite endianness to the one on which the -pattern was compiled. For example, you can compile on an i86 machine and run on -a SPARC machine. When a pattern is reloaded on a host with different -endianness, the confirmation message is changed to: -
- Compiled pattern (byte-inverted) loaded from /some/file --The test suite contains some saved pre-compiled patterns with different -endianness. These are reloaded using "<!" instead of just "<". This suppresses -the "(byte-inverted)" text so that the output is the same on all hosts. It also -forces debugging output once the pattern has been reloaded. - -
-File names for saving and reloading can be absolute or relative, but note that -the shell facility of expanding a file name that starts with a tilde (~) is not -available. -
--The ability to save and reload files in pcretest is intended for testing -and experimentation. It is not intended for production use because only a -single pattern can be written to a file. Furthermore, there is no facility for -supplying custom character tables for use with a reloaded pattern. If the -original pattern was compiled with custom tables, an attempt to match a subject -string using a reloaded pattern is likely to cause pcretest to crash. -Finally, if you attempt to load a file that is not in the correct format, the -result is undefined. -
--pcre(3), pcre16(3), pcre32(3), pcreapi(3), -pcrecallout(3), -pcrejit, pcrematching(3), pcrepartial(d), -pcrepattern(3), pcreprecompile(3). -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 23 February 2017
-
-Copyright © 1997-2017 University of Cambridge.
-
-
-Return to the PCRE index page. -
diff --git a/libs/Pcre16/docs/doc/html/pcreunicode.html b/libs/Pcre16/docs/doc/html/pcreunicode.html deleted file mode 100644 index ab36bc61e3..0000000000 --- a/libs/Pcre16/docs/doc/html/pcreunicode.html +++ /dev/null @@ -1,262 +0,0 @@ - - --Return to the PCRE index page. -
-
-This page is part of the PCRE HTML documentation. It was generated automatically
-from the original man page. If there is any nonsense in it, please consult the
-man page, in case the conversion went wrong.
-
-
-UTF-8, UTF-16, UTF-32, AND UNICODE PROPERTY SUPPORT
-
-
-As well as UTF-8 support, PCRE also supports UTF-16 (from release 8.30) and -UTF-32 (from release 8.32), by means of two additional libraries. They can be -built as well as, or instead of, the 8-bit library. -
--In order process UTF-8 strings, you must build PCRE's 8-bit library with UTF -support, and, in addition, you must call -pcre_compile() -with the PCRE_UTF8 option flag, or the pattern must start with the sequence -(*UTF8) or (*UTF). When either of these is the case, both the pattern and any -subject strings that are matched against it are treated as UTF-8 strings -instead of strings of individual 1-byte characters. -
--In order process UTF-16 or UTF-32 strings, you must build PCRE's 16-bit or -32-bit library with UTF support, and, in addition, you must call -pcre16_compile() -or -pcre32_compile() -with the PCRE_UTF16 or PCRE_UTF32 option flag, as appropriate. Alternatively, -the pattern must start with the sequence (*UTF16), (*UTF32), as appropriate, or -(*UTF), which can be used with either library. When UTF mode is set, both the -pattern and any subject strings that are matched against it are treated as -UTF-16 or UTF-32 strings instead of strings of individual 16-bit or 32-bit -characters. -
--If you compile PCRE with UTF support, but do not use it at run time, the -library will be a bit bigger, but the additional run time overhead is limited -to testing the PCRE_UTF[8|16|32] flag occasionally, so should not be very big. -
--If PCRE is built with Unicode character property support (which implies UTF -support), the escape sequences \p{..}, \P{..}, and \X can be used. -The available properties that can be tested are limited to the general -category properties such as Lu for an upper case letter or Nd for a decimal -number, the Unicode script names such as Arabic or Han, and the derived -properties Any and L&. Full lists is given in the -pcrepattern -and -pcresyntax -documentation. Only the short names for properties are supported. For example, -\p{L} matches a letter. Its Perl synonym, \p{Letter}, is not supported. -Furthermore, in Perl, many properties may optionally be prefixed by "Is", for -compatibility with Perl 5.6. PCRE does not support this. -
--When you set the PCRE_UTF8 flag, the byte strings passed as patterns and -subjects are (by default) checked for validity on entry to the relevant -functions. The entire string is checked before any other processing takes -place. From release 7.3 of PCRE, the check is according the rules of RFC 3629, -which are themselves derived from the Unicode specification. Earlier releases -of PCRE followed the rules of RFC 2279, which allows the full range of 31-bit -values (0 to 0x7FFFFFFF). The current check allows only values in the range U+0 -to U+10FFFF, excluding the surrogate area. (From release 8.33 the so-called -"non-character" code points are no longer excluded because Unicode corrigendum -#9 makes it clear that they should not be.) -
--Characters in the "Surrogate Area" of Unicode are reserved for use by UTF-16, -where they are used in pairs to encode codepoints with values greater than -0xFFFF. The code points that are encoded by UTF-16 pairs are available -independently in the UTF-8 and UTF-32 encodings. (In other words, the whole -surrogate thing is a fudge for UTF-16 which unfortunately messes up UTF-8 and -UTF-32.) -
--If an invalid UTF-8 string is passed to PCRE, an error return is given. At -compile time, the only additional information is the offset to the first byte -of the failing character. The run-time functions pcre_exec() and -pcre_dfa_exec() also pass back this information, as well as a more -detailed reason code if the caller has provided memory in which to do this. -
--In some situations, you may already know that your strings are valid, and -therefore want to skip these checks in order to improve performance, for -example in the case of a long subject string that is being scanned repeatedly. -If you set the PCRE_NO_UTF8_CHECK flag at compile time or at run time, PCRE -assumes that the pattern or subject it is given (respectively) contains only -valid UTF-8 codes. In this case, it does not diagnose an invalid UTF-8 string. -
--Note that passing PCRE_NO_UTF8_CHECK to pcre_compile() just disables the -check for the pattern; it does not also apply to subject strings. If you want -to disable the check for a subject string you must pass this option to -pcre_exec() or pcre_dfa_exec(). -
--If you pass an invalid UTF-8 string when PCRE_NO_UTF8_CHECK is set, the result -is undefined and your program may crash. -
--When you set the PCRE_UTF16 flag, the strings of 16-bit data units that are -passed as patterns and subjects are (by default) checked for validity on entry -to the relevant functions. Values other than those in the surrogate range -U+D800 to U+DFFF are independent code points. Values in the surrogate range -must be used in pairs in the correct manner. -
--If an invalid UTF-16 string is passed to PCRE, an error return is given. At -compile time, the only additional information is the offset to the first data -unit of the failing character. The run-time functions pcre16_exec() and -pcre16_dfa_exec() also pass back this information, as well as a more -detailed reason code if the caller has provided memory in which to do this. -
--In some situations, you may already know that your strings are valid, and -therefore want to skip these checks in order to improve performance. If you set -the PCRE_NO_UTF16_CHECK flag at compile time or at run time, PCRE assumes that -the pattern or subject it is given (respectively) contains only valid UTF-16 -sequences. In this case, it does not diagnose an invalid UTF-16 string. -However, if an invalid string is passed, the result is undefined. -
--When you set the PCRE_UTF32 flag, the strings of 32-bit data units that are -passed as patterns and subjects are (by default) checked for validity on entry -to the relevant functions. This check allows only values in the range U+0 -to U+10FFFF, excluding the surrogate area U+D800 to U+DFFF. -
--If an invalid UTF-32 string is passed to PCRE, an error return is given. At -compile time, the only additional information is the offset to the first data -unit of the failing character. The run-time functions pcre32_exec() and -pcre32_dfa_exec() also pass back this information, as well as a more -detailed reason code if the caller has provided memory in which to do this. -
--In some situations, you may already know that your strings are valid, and -therefore want to skip these checks in order to improve performance. If you set -the PCRE_NO_UTF32_CHECK flag at compile time or at run time, PCRE assumes that -the pattern or subject it is given (respectively) contains only valid UTF-32 -sequences. In this case, it does not diagnose an invalid UTF-32 string. -However, if an invalid string is passed, the result is undefined. -
--1. Codepoints less than 256 can be specified in patterns by either braced or -unbraced hexadecimal escape sequences (for example, \x{b3} or \xb3). Larger -values have to use braced sequences. -
--2. Octal numbers up to \777 are recognized, and in UTF-8 mode they match -two-byte characters for values greater than \177. -
--3. Repeat quantifiers apply to complete UTF characters, not to individual -data units, for example: \x{100}{3}. -
--4. The dot metacharacter matches one UTF character instead of a single data -unit. -
--5. The escape sequence \C can be used to match a single byte in UTF-8 mode, or -a single 16-bit data unit in UTF-16 mode, or a single 32-bit data unit in -UTF-32 mode, but its use can lead to some strange effects because it breaks up -multi-unit characters (see the description of \C in the -pcrepattern -documentation). The use of \C is not supported in the alternative matching -function pcre[16|32]_dfa_exec(), nor is it supported in UTF mode by the -JIT optimization of pcre[16|32]_exec(). If JIT optimization is requested -for a UTF pattern that contains \C, it will not succeed, and so the matching -will be carried out by the normal interpretive function. -
--6. The character escapes \b, \B, \d, \D, \s, \S, \w, and \W correctly -test characters of any code value, but, by default, the characters that PCRE -recognizes as digits, spaces, or word characters remain the same set as in -non-UTF mode, all with values less than 256. This remains true even when PCRE -is built to include Unicode property support, because to do otherwise would -slow down PCRE in many common cases. Note in particular that this applies to -\b and \B, because they are defined in terms of \w and \W. If you really -want to test for a wider sense of, say, "digit", you can use explicit Unicode -property tests such as \p{Nd}. Alternatively, if you set the PCRE_UCP option, -the way that the character escapes work is changed so that Unicode properties -are used to determine which characters match. There are more details in the -section on -generic character types -in the -pcrepattern -documentation. -
--7. Similarly, characters that match the POSIX named character classes are all -low-valued characters, unless the PCRE_UCP option is set. -
--8. However, the horizontal and vertical white space matching escapes (\h, \H, -\v, and \V) do match all the appropriate Unicode characters, whether or not -PCRE_UCP is set. -
--9. Case-insensitive matching applies only to characters whose values are less -than 128, unless PCRE is built with Unicode property support. A few Unicode -characters such as Greek sigma have more than two codepoints that are -case-equivalent. Up to and including PCRE release 8.31, only one-to-one case -mappings were supported, but later releases (with Unicode property support) do -treat as case-equivalent all versions of characters such as Greek sigma. -
-
-Philip Hazel
-
-University Computing Service
-
-Cambridge CB2 3QH, England.
-
-
-Last updated: 27 February 2013
-
-Copyright © 1997-2013 University of Cambridge.
-
-
-Return to the PCRE index page. -
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