From 437835559168a5945a1196161660c439266eb59d Mon Sep 17 00:00:00 2001 From: George Hazan Date: Tue, 16 Jun 2015 11:04:10 +0000 Subject: unified project for pcre16 moved to libs git-svn-id: http://svn.miranda-ng.org/main/trunk@14195 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c --- libs/Pcre16/docs/doc/html/pcre.html | 213 ++++++++++++++++++++++++++++++++++++ 1 file changed, 213 insertions(+) create mode 100644 libs/Pcre16/docs/doc/html/pcre.html (limited to 'libs/Pcre16/docs/doc/html/pcre.html') diff --git a/libs/Pcre16/docs/doc/html/pcre.html b/libs/Pcre16/docs/doc/html/pcre.html new file mode 100644 index 0000000000..c2b29aa812 --- /dev/null +++ b/libs/Pcre16/docs/doc/html/pcre.html @@ -0,0 +1,213 @@ + + +pcre specification + + +

pcre 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. +
+

INTRODUCTION +
SECURITY CONSIDERATIONS +
USER DOCUMENTATION +
AUTHOR +
REVISION +

+
INTRODUCTION
+

+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. +

+
SECURITY CONSIDERATIONS
+

+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. +

+
USER DOCUMENTATION
+

+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: +

+  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. +

+
AUTHOR
+

+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. +

+
REVISION
+

+Return to the PCRE index page. +

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