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diff --git a/plugins/Pcre16/docs/doc/pcregrep.1 b/plugins/Pcre16/docs/doc/pcregrep.1 new file mode 100644 index 0000000000..988667542f --- /dev/null +++ b/plugins/Pcre16/docs/doc/pcregrep.1 @@ -0,0 +1,683 @@ +.TH PCREGREP 1 "03 April 2014" "PCRE 8.35" +.SH NAME +pcregrep - a grep with Perl-compatible regular expressions. +.SH SYNOPSIS +.B pcregrep [options] [long options] [pattern] [path1 path2 ...] +. +.SH DESCRIPTION +.rs +.sp +\fBpcregrep\fP 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 +.\" HREF +\fBpcresyntax\fP(3) +.\" +for a quick-reference summary of pattern syntax, or +.\" HREF +\fBpcrepattern\fP(3) +.\" +for a full description of the syntax and semantics of the regular expressions +that PCRE supports. +.P +Patterns, whether supplied on the command line or in a separate file, are given +without delimiters. For example: +.sp + pcregrep Thursday /etc/motd +.sp +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. +.P +The first argument that follows any option settings is treated as the single +pattern to be matched when neither \fB-e\fP nor \fB-f\fP 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 \fB-e\fP, \fB-f\fP, or an +argument pattern must be provided. +.P +If no files are specified, \fBpcregrep\fP reads the standard input. The +standard input can also be referenced by a name consisting of a single hyphen. +For example: +.sp + pcregrep some-pattern /file1 - /file3 +.sp +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 \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it +possible to search for patterns that span line boundaries. What defines a line +boundary is controlled by the \fB-N\fP (\fB--newline\fP) option. +.P +The amount of memory used for buffering files that are being scanned is +controlled by a parameter that can be set by the \fB--buffer-size\fP option. +The default value for this parameter is specified when \fBpcregrep\fP 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. +.P +Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. +BUFSIZ is defined in \fB<stdio.h>\fP. When there is more than one pattern +(specified by the use of \fB-e\fP and/or \fB-f\fP), each pattern is applied to +each line in the order in which they are defined, except that all the \fB-e\fP +patterns are tried before the \fB-f\fP patterns. +.P +By default, as soon as one pattern matches a line, no further patterns are +considered. However, if \fB--colour\fP (or \fB--color\fP) is used to colour the +matching substrings, or if \fB--only-matching\fP, \fB--file-offsets\fP, or +\fB--line-offsets\fP 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. +.P +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). +.P +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. +.P +If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set, +\fBpcregrep\fP uses the value to set a locale when calling the PCRE library. +The \fB--locale\fP option can be used to override this. +. +. +.SH "SUPPORT FOR COMPRESSED FILES" +.rs +.sp +It is possible to compile \fBpcregrep\fP so that it uses \fBlibz\fP or +\fBlibbz2\fP to read files whose names end in \fB.gz\fP or \fB.bz2\fP, +respectively. You can find out whether your binary has support for one or both +of these file types by running it with the \fB--help\fP option. If the +appropriate support is not present, files are treated as plain text. The +standard input is always so treated. +. +. +.SH "BINARY FILES" +.rs +.sp +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 \fB--binary-files\fP option +for a means of changing the way binary files are handled. +. +. +.SH OPTIONS +.rs +.sp +The order in which some of the options appear can affect the output. For +example, both the \fB-h\fP and \fB-l\fP 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. +.TP 10 +\fB--\fP +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. +.TP +\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP +Output \fInumber\fP 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 \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP +guarantees to have up to 8K of following text available for context output. +.TP +\fB-a\fP, \fB--text\fP +Treat binary files as text. This is equivalent to +\fB--binary-files\fP=\fItext\fP. +.TP +\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP +Output \fInumber\fP 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 \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP +guarantees to have up to 8K of preceding text available for context output. +.TP +\fB--binary-files=\fP\fIword\fP +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 \fB-a\fP or \fB--text\fP 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 +\fB-I\fP option, binary files are not processed at all; they are assumed not to +be of interest. +.TP +\fB--buffer-size=\fP\fInumber\fP +Set the parameter that controls how much memory is used for buffering files +that are being scanned. +.TP +\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP +Output \fInumber\fP lines of context both before and after each matching line. +This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value. +.TP +\fB-c\fP, \fB--count\fP +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 +\fB--files-with-matches\fP option is also used, only those files whose counts +are greater than zero are listed. When \fB-c\fP is used, the \fB-A\fP, +\fB-B\fP, and \fB-C\fP options are ignored. +.TP +\fB--colour\fP, \fB--color\fP +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. +.TP +\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP +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 \fBpcregrep\fP has to search for all possible matches in a line, not +just one, in order to colour them all. +.sp +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. +.TP +\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP +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). +.TP +\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP +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 \fB-r\fP 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. +.TP +\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP, \fB--regexp=\fP\fIpattern\fP +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 \fB-e\fP 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. +.sp +If \fB-f\fP is used with \fB-e\fP, 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 \fB-e\fP 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, \fBpcregrep\fP 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 \fB-o\fP or \fB--colo(u)r\fP to show the part(s) +of the line that matched. +.TP +\fB--exclude\fP=\fIpattern\fP +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 \fB--file-list\fP, 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 \fB-F\fP, \fB-w\fP, and \fB-x\fP 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 \fB--include\fP +and an \fB--exclude\fP pattern, it is excluded. There is no short form for this +option. +.TP +\fB--exclude-from=\fP\fIfilename\fP +Treat each non-empty line of the file as the data for an \fB--exclude\fP +option. What constitutes a newline when reading the file is the operating +system's default. The \fB--newline\fP 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. +.TP +\fB--exclude-dir\fP=\fIpattern\fP +Directories whose names match the pattern are skipped without being processed, +whatever the setting of the \fB--recursive\fP option. This applies to all +directories, whether listed on the command line, obtained from +\fB--file-list\fP, 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 \fB-F\fP, \fB-w\fP, and \fB-x\fP 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 \fB--include-dir\fP +and \fB--exclude-dir\fP, it is excluded. There is no short form for this +option. +.TP +\fB-F\fP, \fB--fixed-strings\fP +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 \fB--newline\fP option. The \fB-w\fP (match +as a word) and \fB-x\fP (match whole line) options can be used with \fB-F\fP. +They apply to each of the fixed strings. A line is selected if any of the fixed +strings are found in it (subject to \fB-w\fP or \fB-x\fP, 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 \fB--include\fP or +\fB--exclude\fP options. +.TP +\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP +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 \fB--newline\fP 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 \fB-e\fP above. +.sp +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 \fB-f\fP is used, patterns +specified on the command line using \fB-e\fP 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. +.TP +\fB--file-list\fP=\fIfilename\fP +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 \fB--file\fP and \fB--file-list\fP 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. +.TP +\fB--file-offsets\fP +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 \fB-A\fP, \fB-B\fP, and \fB-C\fP +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 \fB--line-offsets\fP +and \fB--only-matching\fP. +.TP +\fB-H\fP, \fB--with-filename\fP +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. +.TP +\fB-h\fP, \fB--no-filename\fP +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. +.TP +\fB--help\fP +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. +.TP +\fB-I\fP +Treat binary files as never matching. This is equivalent to +\fB--binary-files\fP=\fIwithout-match\fP. +.TP +\fB-i\fP, \fB--ignore-case\fP +Ignore upper/lower case distinctions during comparisons. +.TP +\fB--include\fP=\fIpattern\fP +If any \fB--include\fP patterns are specified, the only files that are +processed are those that match one of the patterns (and do not match an +\fB--exclude\fP pattern). This option does not affect directories, but it +applies to all files, whether listed on the command line, obtained from +\fB--file-list\fP, 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 \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not apply to +this pattern. The option may be given any number of times. If a file name +matches both an \fB--include\fP and an \fB--exclude\fP pattern, it is excluded. +There is no short form for this option. +.TP +\fB--include-from=\fP\fIfilename\fP +Treat each non-empty line of the file as the data for an \fB--include\fP +option. What constitutes a newline for this purpose is the operating system's +default. The \fB--newline\fP option has no effect on this option. This option +may be given any number of times; all the files are read. +.TP +\fB--include-dir\fP=\fIpattern\fP +If any \fB--include-dir\fP patterns are specified, the only directories that +are processed are those that match one of the patterns (and do not match an +\fB--exclude-dir\fP pattern). This applies to all directories, whether listed +on the command line, obtained from \fB--file-list\fP, 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 \fB-F\fP, +\fB-w\fP, and \fB-x\fP options do not apply to this pattern. The option may be +given any number of times. If a directory matches both \fB--include-dir\fP and +\fB--exclude-dir\fP, it is excluded. There is no short form for this option. +.TP +\fB-L\fP, \fB--files-without-match\fP +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. +.TP +\fB-l\fP, \fB--files-with-matches\fP +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 \fB-c\fP (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 \fB-c\fP is a way of suppressing the listing of files with no matches. +.TP +\fB--label\fP=\fIname\fP +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. +.TP +\fB--line-buffered\fP +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 \fBpcregrep\fP 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 +\fBpcregrep\fP to buffer up large amounts of data. However, its use will affect +performance, and the \fB-M\fP (multiline) option ceases to work. +.TP +\fB--line-offsets\fP +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 \fB-n\fP option), and the +offset and length are separated by a comma. In this mode, no context is shown. +That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP 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 \fB--file-offsets\fP and \fB--only-matching\fP. +.TP +\fB--locale\fP=\fIlocale-name\fP +This option specifies a locale to be used for pattern matching. It overrides +the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP 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. +.TP +\fB--match-limit\fP=\fInumber\fP +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 \fBpcre_exec()\fP function that is called by \fBpcregrep\fP to do +the matching has two parameters that can limit the resources that it uses. +.sp +The \fB--match-limit\fP 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 \fBmatch()\fP which it calls repeatedly (sometimes recursively). The +limit set by \fB--match-limit\fP 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. +.sp +The \fB--recursion-limit\fP option is similar to \fB--match-limit\fP, but +instead of limiting the total number of times that \fBmatch()\fP 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 \fBmatch()\fP are recursive. This limit is +of use only if it is set smaller than \fB--match-limit\fP. +.sp +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. +.TP +\fB-M\fP, \fB--multiline\fP +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. +.sp +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 \fBpcregrep\fP buffers the input file as it scans it. However, +\fBpcregrep\fP 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.) +.TP +\fB-N\fP \fInewline-type\fP, \fB--newline\fP=\fInewline-type\fP +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). +.sp +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, \fBpcregrep\fP uses the library's default. +The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This +makes it possible to use \fBpcregrep\fP 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, +\fBpcregrep\fP may behave in strange ways. Note that this option does not +apply to files specified by the \fB-f\fP, \fB--exclude-from\fP, or +\fB--include-from\fP options, which are expected to use the operating system's +standard newline sequence. +.TP +\fB-n\fP, \fB--line-number\fP +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 +\fB--line-offsets\fP is used. +.TP +\fB--no-jit\fP +If the PCRE library is built with support for just-in-time compiling (which +speeds up matching), \fBpcregrep\fP 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. +.TP +\fB-o\fP, \fB--only-matching\fP +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 \fB-A\fP, \fB-B\fP, and +\fB-C\fP options are ignored. If there is more than one match in a line, each +of them is shown separately. If \fB-o\fP is combined with \fB-v\fP (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 \fB--file-offsets\fP and \fB--line-offsets\fP. +.TP +\fB-o\fP\fInumber\fP, \fB--only-matching\fP=\fInumber\fP +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 \fB-o\fP 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. +.sp +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). +.TP +\fB--om-separator\fP=\fItext\fP +Specify a separating string for multiple occurrences of \fB-o\fP. The default +is an empty string. Separating strings are never coloured. +.TP +\fB-q\fP, \fB--quiet\fP +Work quietly, that is, display nothing except error messages. The exit +status indicates whether or not any matches were found. +.TP +\fB-r\fP, \fB--recursive\fP +If any given path is a directory, recursively scan the files it contains, +taking note of any \fB--include\fP and \fB--exclude\fP 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 \fB-d\fP +option to "recurse". +.TP +\fB--recursion-limit\fP=\fInumber\fP +See \fB--match-limit\fP above. +.TP +\fB-s\fP, \fB--no-messages\fP +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. +.TP +\fB-u\fP, \fB--utf-8\fP +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 \fB--exclude\fP and +\fB--include\fP options) and all subject lines that are scanned must be valid +strings of UTF-8 characters. +.TP +\fB-V\fP, \fB--version\fP +Write the version numbers of \fBpcregrep\fP and the PCRE library to the +standard output and then exit. Anything else on the command line is +ignored. +.TP +\fB-v\fP, \fB--invert-match\fP +Invert the sense of the match, so that lines which do \fInot\fP match any of +the patterns are the ones that are found. +.TP +\fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP +Force the patterns to match only whole words. This is equivalent to having \eb +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 \fB--include\fP or \fB--exclude\fP options. +.TP +\fB-x\fP, \fB--line-regex\fP, \fB--line-regexp\fP +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 \fB--include\fP or \fB--exclude\fP options. +. +. +.SH "ENVIRONMENT VARIABLES" +.rs +.sp +The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that +order, for a locale. The first one that is set is used. This can be overridden +by the \fB--locale\fP option. If no locale is set, the PCRE library's default +(usually the "C" locale) is used. +. +. +.SH "NEWLINES" +.rs +.sp +The \fB-N\fP (\fB--newline\fP) option allows \fBpcregrep\fP 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 \fB-f\fP, +\fB--exclude-from\fP, or \fB--include-from\fP options, which are assumed to use +the operating system's standard newline sequence, nor does it affect the way in +which \fBpcregrep\fP writes informational messages to the standard error and +output streams. For these it uses the string "\en" to indicate newlines, +relying on the C I/O library to convert this to an appropriate sequence. +. +. +.SH "OPTIONS COMPATIBILITY" +.rs +.sp +Many of the short and long forms of \fBpcregrep\fP's options are the same +as in the GNU \fBgrep\fP program. Any long option of the form +\fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP +(PCRE terminology). However, the \fB--file-list\fP, \fB--file-offsets\fP, +\fB--include-dir\fP, \fB--line-offsets\fP, \fB--locale\fP, \fB--match-limit\fP, +\fB-M\fP, \fB--multiline\fP, \fB-N\fP, \fB--newline\fP, \fB--om-separator\fP, +\fB--recursion-limit\fP, \fB-u\fP, and \fB--utf-8\fP options are specific to +\fBpcregrep\fP, as is the use of the \fB--only-matching\fP option with a +capturing parentheses number. +.P +Although most of the common options work the same way, a few are different in +\fBpcregrep\fP. For example, the \fB--include\fP option's argument is a glob +for GNU \fBgrep\fP, but a regular expression for \fBpcregrep\fP. If both the +\fB-c\fP and \fB-l\fP options are given, GNU grep lists only file names, +without counts, but \fBpcregrep\fP gives the counts. +. +. +.SH "OPTIONS WITH DATA" +.rs +.sp +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: +.sp + -f/some/file + -f /some/file +.sp +The exception is the \fB-o\fP 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. +.P +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: +.sp + --file=/some/file + --file /some/file +.sp +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. +.P +The exceptions to the above are the \fB--colour\fP (or \fB--color\fP) and +\fB--only-matching\fP 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 \fBpcregrep\fP will assume that it has no data. +. +. +.SH "MATCHING ERRORS" +.rs +.sp +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+)*\ed 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, \fBpcregrep\fP outputs an error +message and the line that caused the problem to the standard error stream. If +there are more than 20 such errors, \fBpcregrep\fP gives up. +.P +The \fB--match-limit\fP option of \fBpcregrep\fP can be used to set the overall +resource limit; there is a second option called \fB--recursion-limit\fP that +sets a limit on the amount of memory (usually stack) that is used (see the +discussion of these options above). +. +. +.SH DIAGNOSTICS +.rs +.sp +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 +\fB-s\fP option to suppress error messages about inaccessible files does not +affect the return code. +. +. +.SH "SEE ALSO" +.rs +.sp +\fBpcrepattern\fP(3), \fBpcresyntax\fP(3), \fBpcretest\fP(1). +. +. +.SH AUTHOR +.rs +.sp +.nf +Philip Hazel +University Computing Service +Cambridge CB2 3QH, England. +.fi +. +. +.SH REVISION +.rs +.sp +.nf +Last updated: 03 April 2014 +Copyright (c) 1997-2014 University of Cambridge. +.fi |