diff options
Diffstat (limited to 'doc/html/pcregrep.html')
| -rw-r--r-- | doc/html/pcregrep.html | 759 |
1 files changed, 759 insertions, 0 deletions
diff --git a/doc/html/pcregrep.html b/doc/html/pcregrep.html new file mode 100644 index 0000000..dacbb49 --- /dev/null +++ b/doc/html/pcregrep.html @@ -0,0 +1,759 @@ +<html> +<head> +<title>pcregrep specification</title> +</head> +<body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB"> +<h1>pcregrep man page</h1> +<p> +Return to the <a href="index.html">PCRE index page</a>. +</p> +<p> +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. +<br> +<ul> +<li><a name="TOC1" href="#SEC1">SYNOPSIS</a> +<li><a name="TOC2" href="#SEC2">DESCRIPTION</a> +<li><a name="TOC3" href="#SEC3">SUPPORT FOR COMPRESSED FILES</a> +<li><a name="TOC4" href="#SEC4">BINARY FILES</a> +<li><a name="TOC5" href="#SEC5">OPTIONS</a> +<li><a name="TOC6" href="#SEC6">ENVIRONMENT VARIABLES</a> +<li><a name="TOC7" href="#SEC7">NEWLINES</a> +<li><a name="TOC8" href="#SEC8">OPTIONS COMPATIBILITY</a> +<li><a name="TOC9" href="#SEC9">OPTIONS WITH DATA</a> +<li><a name="TOC10" href="#SEC10">MATCHING ERRORS</a> +<li><a name="TOC11" href="#SEC11">DIAGNOSTICS</a> +<li><a name="TOC12" href="#SEC12">SEE ALSO</a> +<li><a name="TOC13" href="#SEC13">AUTHOR</a> +<li><a name="TOC14" href="#SEC14">REVISION</a> +</ul> +<br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br> +<P> +<b>pcregrep [options] [long options] [pattern] [path1 path2 ...]</b> +</P> +<br><a name="SEC2" href="#TOC1">DESCRIPTION</a><br> +<P> +<b>pcregrep</b> 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 +<a href="pcresyntax.html"><b>pcresyntax</b>(3)</a> +for a quick-reference summary of pattern syntax, or +<a href="pcrepattern.html"><b>pcrepattern</b>(3)</a> +for a full description of the syntax and semantics of the regular expressions +that PCRE supports. +</P> +<P> +Patterns, whether supplied on the command line or in a separate file, are given +without delimiters. For example: +<pre> + pcregrep Thursday /etc/motd +</pre> +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> +<P> +The first argument that follows any option settings is treated as the single +pattern to be matched when neither <b>-e</b> nor <b>-f</b> 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 <b>-e</b>, <b>-f</b>, or an +argument pattern must be provided. +</P> +<P> +If no files are specified, <b>pcregrep</b> reads the standard input. The +standard input can also be referenced by a name consisting of a single hyphen. +For example: +<pre> + pcregrep some-pattern /file1 - /file3 +</pre> +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 <b>pcregrep</b> behaves. In particular, the <b>-M</b> option makes it +possible to search for patterns that span line boundaries. What defines a line +boundary is controlled by the <b>-N</b> (<b>--newline</b>) option. +</P> +<P> +The amount of memory used for buffering files that are being scanned is +controlled by a parameter that can be set by the <b>--buffer-size</b> option. +The default value for this parameter is specified when <b>pcregrep</b> 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> +<P> +Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. +BUFSIZ is defined in <b><stdio.h></b>. When there is more than one pattern +(specified by the use of <b>-e</b> and/or <b>-f</b>), each pattern is applied to +each line in the order in which they are defined, except that all the <b>-e</b> +patterns are tried before the <b>-f</b> patterns. +</P> +<P> +By default, as soon as one pattern matches a line, no further patterns are +considered. However, if <b>--colour</b> (or <b>--color</b>) is used to colour the +matching substrings, or if <b>--only-matching</b>, <b>--file-offsets</b>, or +<b>--line-offsets</b> 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> +<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> +<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> +<P> +If the <b>LC_ALL</b> or <b>LC_CTYPE</b> environment variable is set, +<b>pcregrep</b> uses the value to set a locale when calling the PCRE library. +The <b>--locale</b> option can be used to override this. +</P> +<br><a name="SEC3" href="#TOC1">SUPPORT FOR COMPRESSED FILES</a><br> +<P> +It is possible to compile <b>pcregrep</b> so that it uses <b>libz</b> or +<b>libbz2</b> to read files whose names end in <b>.gz</b> or <b>.bz2</b>, +respectively. You can find out whether your binary has support for one or both +of these file types by running it with the <b>--help</b> option. If the +appropriate support is not present, files are treated as plain text. The +standard input is always so treated. +</P> +<br><a name="SEC4" href="#TOC1">BINARY FILES</a><br> +<P> +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 <b>--binary-files</b> option +for a means of changing the way binary files are handled. +</P> +<br><a name="SEC5" href="#TOC1">OPTIONS</a><br> +<P> +The order in which some of the options appear can affect the output. For +example, both the <b>-h</b> and <b>-l</b> 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. +</P> +<P> +<b>--</b> +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. +</P> +<P> +<b>-A</b> <i>number</i>, <b>--after-context=</b><i>number</i> +Output <i>number</i> 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 <i>number</i> is expected to be relatively small. However, <b>pcregrep</b> +guarantees to have up to 8K of following text available for context output. +</P> +<P> +<b>-a</b>, <b>--text</b> +Treat binary files as text. This is equivalent to +<b>--binary-files</b>=<i>text</i>. +</P> +<P> +<b>-B</b> <i>number</i>, <b>--before-context=</b><i>number</i> +Output <i>number</i> 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 <i>number</i> is expected to be relatively small. However, <b>pcregrep</b> +guarantees to have up to 8K of preceding text available for context output. +</P> +<P> +<b>--binary-files=</b><i>word</i> +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 <b>-a</b> or <b>--text</b> 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 +<b>-I</b> option, binary files are not processed at all; they are assumed not to +be of interest. +</P> +<P> +<b>--buffer-size=</b><i>number</i> +Set the parameter that controls how much memory is used for buffering files +that are being scanned. +</P> +<P> +<b>-C</b> <i>number</i>, <b>--context=</b><i>number</i> +Output <i>number</i> lines of context both before and after each matching line. +This is equivalent to setting both <b>-A</b> and <b>-B</b> to the same value. +</P> +<P> +<b>-c</b>, <b>--count</b> +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 +<b>--files-with-matches</b> option is also used, only those files whose counts +are greater than zero are listed. When <b>-c</b> is used, the <b>-A</b>, +<b>-B</b>, and <b>-C</b> options are ignored. +</P> +<P> +<b>--colour</b>, <b>--color</b> +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. +</P> +<P> +<b>--colour=</b><i>value</i>, <b>--color=</b><i>value</i> +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 <b>pcregrep</b> has to search for all possible matches in a line, not +just one, in order to colour them all. +<br> +<br> +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. +</P> +<P> +<b>-D</b> <i>action</i>, <b>--devices=</b><i>action</i> +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). +</P> +<P> +<b>-d</b> <i>action</i>, <b>--directories=</b><i>action</i> +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 <b>-r</b> 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. +</P> +<P> +<b>-e</b> <i>pattern</i>, <b>--regex=</b><i>pattern</i>, <b>--regexp=</b><i>pattern</i> +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 <b>-e</b> 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. +<br> +<br> +If <b>-f</b> is used with <b>-e</b>, 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 <b>-e</b> 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, <b>pcregrep</b> 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 <b>-o</b> or <b>--colo(u)r</b> to show the part(s) +of the line that matched. +</P> +<P> +<b>--exclude</b>=<i>pattern</i> +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 <b>--file-list</b>, 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 <b>-F</b>, <b>-w</b>, and <b>-x</b> 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 <b>--include</b> +and an <b>--exclude</b> pattern, it is excluded. There is no short form for this +option. +</P> +<P> +<b>--exclude-from=</b><i>filename</i> +Treat each non-empty line of the file as the data for an <b>--exclude</b> +option. What constitutes a newline when reading the file is the operating +system's default. The <b>--newline</b> 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. +</P> +<P> +<b>--exclude-dir</b>=<i>pattern</i> +Directories whose names match the pattern are skipped without being processed, +whatever the setting of the <b>--recursive</b> option. This applies to all +directories, whether listed on the command line, obtained from +<b>--file-list</b>, 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 <b>-F</b>, <b>-w</b>, and <b>-x</b> 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 <b>--include-dir</b> +and <b>--exclude-dir</b>, it is excluded. There is no short form for this +option. +</P> +<P> +<b>-F</b>, <b>--fixed-strings</b> +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 <b>--newline</b> option. The <b>-w</b> (match +as a word) and <b>-x</b> (match whole line) options can be used with <b>-F</b>. +They apply to each of the fixed strings. A line is selected if any of the fixed +strings are found in it (subject to <b>-w</b> or <b>-x</b>, 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 <b>--include</b> or +<b>--exclude</b> options. +</P> +<P> +<b>-f</b> <i>filename</i>, <b>--file=</b><i>filename</i> +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 <b>--newline</b> 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 <b>-e</b> above. +<br> +<br> +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 <b>-f</b> is used, patterns +specified on the command line using <b>-e</b> 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. +</P> +<P> +<b>--file-list</b>=<i>filename</i> +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 <b>--file</b> and <b>--file-list</b> 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. +</P> +<P> +<b>--file-offsets</b> +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 <b>-A</b>, <b>-B</b>, and <b>-C</b> +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 <b>--line-offsets</b> +and <b>--only-matching</b>. +</P> +<P> +<b>-H</b>, <b>--with-filename</b> +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. +</P> +<P> +<b>-h</b>, <b>--no-filename</b> +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. +</P> +<P> +<b>--help</b> +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. +</P> +<P> +<b>-I</b> +Treat binary files as never matching. This is equivalent to +<b>--binary-files</b>=<i>without-match</i>. +</P> +<P> +<b>-i</b>, <b>--ignore-case</b> +Ignore upper/lower case distinctions during comparisons. +</P> +<P> +<b>--include</b>=<i>pattern</i> +If any <b>--include</b> patterns are specified, the only files that are +processed are those that match one of the patterns (and do not match an +<b>--exclude</b> pattern). This option does not affect directories, but it +applies to all files, whether listed on the command line, obtained from +<b>--file-list</b>, 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 <b>-F</b>, <b>-w</b>, and <b>-x</b> options do not apply to +this pattern. The option may be given any number of times. If a file name +matches both an <b>--include</b> and an <b>--exclude</b> pattern, it is excluded. +There is no short form for this option. +</P> +<P> +<b>--include-from=</b><i>filename</i> +Treat each non-empty line of the file as the data for an <b>--include</b> +option. What constitutes a newline for this purpose is the operating system's +default. The <b>--newline</b> option has no effect on this option. This option +may be given any number of times; all the files are read. +</P> +<P> +<b>--include-dir</b>=<i>pattern</i> +If any <b>--include-dir</b> patterns are specified, the only directories that +are processed are those that match one of the patterns (and do not match an +<b>--exclude-dir</b> pattern). This applies to all directories, whether listed +on the command line, obtained from <b>--file-list</b>, 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 <b>-F</b>, +<b>-w</b>, and <b>-x</b> options do not apply to this pattern. The option may be +given any number of times. If a directory matches both <b>--include-dir</b> and +<b>--exclude-dir</b>, it is excluded. There is no short form for this option. +</P> +<P> +<b>-L</b>, <b>--files-without-match</b> +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. +</P> +<P> +<b>-l</b>, <b>--files-with-matches</b> +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 <b>-c</b> (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 <b>-c</b> is a way of suppressing the listing of files with no matches. +</P> +<P> +<b>--label</b>=<i>name</i> +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. +</P> +<P> +<b>--line-buffered</b> +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 <b>pcregrep</b> 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 +<b>pcregrep</b> to buffer up large amounts of data. However, its use will affect +performance, and the <b>-M</b> (multiline) option ceases to work. +</P> +<P> +<b>--line-offsets</b> +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 <b>-n</b> option), and the +offset and length are separated by a comma. In this mode, no context is shown. +That is, the <b>-A</b>, <b>-B</b>, and <b>-C</b> 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 <b>--file-offsets</b> and <b>--only-matching</b>. +</P> +<P> +<b>--locale</b>=<i>locale-name</i> +This option specifies a locale to be used for pattern matching. It overrides +the value in the <b>LC_ALL</b> or <b>LC_CTYPE</b> 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. +</P> +<P> +<b>--match-limit</b>=<i>number</i> +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 <b>pcre_exec()</b> function that is called by <b>pcregrep</b> to do +the matching has two parameters that can limit the resources that it uses. +<br> +<br> +The <b>--match-limit</b> 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 <b>match()</b> which it calls repeatedly (sometimes recursively). The +limit set by <b>--match-limit</b> 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. +<br> +<br> +The <b>--recursion-limit</b> option is similar to <b>--match-limit</b>, but +instead of limiting the total number of times that <b>match()</b> 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 <b>match()</b> are recursive. This limit is +of use only if it is set smaller than <b>--match-limit</b>. +<br> +<br> +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. +</P> +<P> +<b>-M</b>, <b>--multiline</b> +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. +<br> +<br> +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 <b>pcregrep</b> buffers the input file as it scans it. However, +<b>pcregrep</b> 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.) +</P> +<P> +<b>-N</b> <i>newline-type</i>, <b>--newline</b>=<i>newline-type</i> +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). +<br> +<br> +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, <b>pcregrep</b> uses the library's default. +The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This +makes it possible to use <b>pcregrep</b> 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, +<b>pcregrep</b> may behave in strange ways. Note that this option does not +apply to files specified by the <b>-f</b>, <b>--exclude-from</b>, or +<b>--include-from</b> options, which are expected to use the operating system's +standard newline sequence. +</P> +<P> +<b>-n</b>, <b>--line-number</b> +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 +<b>--line-offsets</b> is used. +</P> +<P> +<b>--no-jit</b> +If the PCRE library is built with support for just-in-time compiling (which +speeds up matching), <b>pcregrep</b> 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. +</P> +<P> +<b>-o</b>, <b>--only-matching</b> +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 <b>-A</b>, <b>-B</b>, and +<b>-C</b> options are ignored. If there is more than one match in a line, each +of them is shown separately. If <b>-o</b> is combined with <b>-v</b> (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 <b>--file-offsets</b> and <b>--line-offsets</b>. +</P> +<P> +<b>-o</b><i>number</i>, <b>--only-matching</b>=<i>number</i> +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 <b>-o</b> 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. +<br> +<br> +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). +</P> +<P> +<b>--om-separator</b>=<i>text</i> +Specify a separating string for multiple occurrences of <b>-o</b>. The default +is an empty string. Separating strings are never coloured. +</P> +<P> +<b>-q</b>, <b>--quiet</b> +Work quietly, that is, display nothing except error messages. The exit +status indicates whether or not any matches were found. +</P> +<P> +<b>-r</b>, <b>--recursive</b> +If any given path is a directory, recursively scan the files it contains, +taking note of any <b>--include</b> and <b>--exclude</b> 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 <b>-d</b> +option to "recurse". +</P> +<P> +<b>--recursion-limit</b>=<i>number</i> +See <b>--match-limit</b> above. +</P> +<P> +<b>-s</b>, <b>--no-messages</b> +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. +</P> +<P> +<b>-u</b>, <b>--utf-8</b> +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 <b>--exclude</b> and +<b>--include</b> options) and all subject lines that are scanned must be valid +strings of UTF-8 characters. +</P> +<P> +<b>-V</b>, <b>--version</b> +Write the version numbers of <b>pcregrep</b> and the PCRE library to the +standard output and then exit. Anything else on the command line is +ignored. +</P> +<P> +<b>-v</b>, <b>--invert-match</b> +Invert the sense of the match, so that lines which do <i>not</i> match any of +the patterns are the ones that are found. +</P> +<P> +<b>-w</b>, <b>--word-regex</b>, <b>--word-regexp</b> +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 <b>--include</b> or <b>--exclude</b> options. +</P> +<P> +<b>-x</b>, <b>--line-regex</b>, <b>--line-regexp</b> +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 <b>--include</b> or <b>--exclude</b> options. +</P> +<br><a name="SEC6" href="#TOC1">ENVIRONMENT VARIABLES</a><br> +<P> +The environment variables <b>LC_ALL</b> and <b>LC_CTYPE</b> are examined, in that +order, for a locale. The first one that is set is used. This can be overridden +by the <b>--locale</b> option. If no locale is set, the PCRE library's default +(usually the "C" locale) is used. +</P> +<br><a name="SEC7" href="#TOC1">NEWLINES</a><br> +<P> +The <b>-N</b> (<b>--newline</b>) option allows <b>pcregrep</b> 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 <b>-f</b>, +<b>--exclude-from</b>, or <b>--include-from</b> options, which are assumed to use +the operating system's standard newline sequence, nor does it affect the way in +which <b>pcregrep</b> 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. +</P> +<br><a name="SEC8" href="#TOC1">OPTIONS COMPATIBILITY</a><br> +<P> +Many of the short and long forms of <b>pcregrep</b>'s options are the same +as in the GNU <b>grep</b> program. Any long option of the form +<b>--xxx-regexp</b> (GNU terminology) is also available as <b>--xxx-regex</b> +(PCRE terminology). However, the <b>--file-list</b>, <b>--file-offsets</b>, +<b>--include-dir</b>, <b>--line-offsets</b>, <b>--locale</b>, <b>--match-limit</b>, +<b>-M</b>, <b>--multiline</b>, <b>-N</b>, <b>--newline</b>, <b>--om-separator</b>, +<b>--recursion-limit</b>, <b>-u</b>, and <b>--utf-8</b> options are specific to +<b>pcregrep</b>, as is the use of the <b>--only-matching</b> option with a +capturing parentheses number. +</P> +<P> +Although most of the common options work the same way, a few are different in +<b>pcregrep</b>. For example, the <b>--include</b> option's argument is a glob +for GNU <b>grep</b>, but a regular expression for <b>pcregrep</b>. If both the +<b>-c</b> and <b>-l</b> options are given, GNU grep lists only file names, +without counts, but <b>pcregrep</b> gives the counts. +</P> +<br><a name="SEC9" href="#TOC1">OPTIONS WITH DATA</a><br> +<P> +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: +<pre> + -f/some/file + -f /some/file +</pre> +The exception is the <b>-o</b> 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> +<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: +<pre> + --file=/some/file + --file /some/file +</pre> +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> +<P> +The exceptions to the above are the <b>--colour</b> (or <b>--color</b>) and +<b>--only-matching</b> 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 <b>pcregrep</b> will assume that it has no data. +</P> +<br><a name="SEC10" href="#TOC1">MATCHING ERRORS</a><br> +<P> +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, <b>pcregrep</b> outputs an error +message and the line that caused the problem to the standard error stream. If +there are more than 20 such errors, <b>pcregrep</b> gives up. +</P> +<P> +The <b>--match-limit</b> option of <b>pcregrep</b> can be used to set the overall +resource limit; there is a second option called <b>--recursion-limit</b> that +sets a limit on the amount of memory (usually stack) that is used (see the +discussion of these options above). +</P> +<br><a name="SEC11" href="#TOC1">DIAGNOSTICS</a><br> +<P> +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 +<b>-s</b> option to suppress error messages about inaccessible files does not +affect the return code. +</P> +<br><a name="SEC12" href="#TOC1">SEE ALSO</a><br> +<P> +<b>pcrepattern</b>(3), <b>pcresyntax</b>(3), <b>pcretest</b>(1). +</P> +<br><a name="SEC13" href="#TOC1">AUTHOR</a><br> +<P> +Philip Hazel +<br> +University Computing Service +<br> +Cambridge CB2 3QH, England. +<br> +</P> +<br><a name="SEC14" href="#TOC1">REVISION</a><br> +<P> +Last updated: 03 April 2014 +<br> +Copyright © 1997-2014 University of Cambridge. +<br> +<p> +Return to the <a href="index.html">PCRE index page</a>. +</p> |