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Update pcre2grep documentation to give more details of -M matching.

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Philip.Hazel 2015-01-03 17:40:06 +00:00
parent 5a18651441
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3 changed files with 405 additions and 331 deletions
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@ -67,22 +67,23 @@ If no files are specified, <b>pcre2grep</b> reads the standard input. The
standard input can also be referenced by a name consisting of a single hyphen. standard input can also be referenced by a name consisting of a single hyphen.
For example: For example:
<pre> <pre>
pcre2grep some-pattern /file1 - /file3 pcre2grep some-pattern file1 - file3
</pre> </pre>
By default, each line that matches a pattern is copied to the standard Input files are searched line by line. By default, each line that matches a
output, and if there is more than one file, the file name is output at the pattern is copied to the standard output, and if there is more than one file,
start of each line, followed by a colon. However, there are options that can the file name is output at the start of each line, followed by a colon.
change how <b>pcre2grep</b> behaves. In particular, the <b>-M</b> option makes it However, there are options that can change how <b>pcre2grep</b> behaves. In
possible to search for patterns that span line boundaries. What defines a line particular, the <b>-M</b> option makes it possible to search for strings that
boundary is controlled by the <b>-N</b> (<b>--newline</b>) option. span line boundaries. What defines a line boundary is controlled by the
<b>-N</b> (<b>--newline</b>) option.
</P> </P>
<P> <P>
The amount of memory used for buffering files that are being scanned is 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. 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>pcre2grep</b> is built, The default value for this parameter is specified when <b>pcre2grep</b> is
with the default default being 20K. A block of memory three times this size is built, with the default default being 20K. A block of memory three times this
used (to allow for buffering "before" and "after" lines). An error occurs if a size is used (to allow for buffering "before" and "after" lines). An error
line overflows the buffer. occurs if a line overflows the buffer.
</P> </P>
<P> <P>
Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater.
@ -149,11 +150,11 @@ to signify multiplication by 1024 or 1024*1024 respectively.
<b>--</b> <b>--</b>
This terminates the list of options. It is useful if the next item on the 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 command line starts with a hyphen but is not an option. This allows for the
processing of patterns and filenames that start with hyphens. processing of patterns and file names that start with hyphens.
</P> </P>
<P> <P>
<b>-A</b> <i>number</i>, <b>--after-context=</b><i>number</i> <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 Output <i>number</i> lines of context after each matching line. If file names
and/or line numbers are being output, a hyphen separator is used instead of a 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 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 group of lines, unless they are in fact contiguous in the input file. The value
@ -167,7 +168,7 @@ Treat binary files as text. This is equivalent to
</P> </P>
<P> <P>
<b>-B</b> <i>number</i>, <b>--before-context=</b><i>number</i> <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 Output <i>number</i> lines of context before each matching line. If file names
and/or line numbers are being output, a hyphen separator is used instead of a 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 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 group of lines, unless they are in fact contiguous in the input file. The value
@ -184,7 +185,8 @@ 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 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 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 <b>-I</b> option, binary files are not processed at all; they are assumed not to
be of interest. be of interest and are skipped without causing any output or affecting the
return code.
</P> </P>
<P> <P>
<b>--buffer-size=</b><i>number</i> <b>--buffer-size=</b><i>number</i>
@ -198,10 +200,15 @@ This is equivalent to setting both <b>-A</b> and <b>-B</b> to the same value.
</P> </P>
<P> <P>
<b>-c</b>, <b>--count</b> <b>-c</b>, <b>--count</b>
Do not output individual lines from the files that are being scanned; instead Do not output lines from the files that are being scanned; instead output the
output the number of lines that would otherwise have been shown. If no lines number of matches (or non-matches if <b>-v</b> is used) that would otherwise
are selected, the number zero is output. If several files are are being have caused lines to be shown. By default, this count is the same as the number
scanned, a count is output for each of them. However, if the of suppressed lines, but if the <b>-M</b> (multiline) option is used (without
<b>-v</b>), there may be more suppressed lines than the number of matches.
<br>
<br>
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 <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>, 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. <b>-B</b>, and <b>-C</b> options are ignored.
@ -271,10 +278,10 @@ of the line that matched.
Files (but not directories) whose names match the pattern are skipped without 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, 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 obtained from <b>--file-list</b>, or by scanning a directory. The pattern is a
PCRE2 regular expression, and is matched against the final component of the file PCRE2 regular expression, and is matched against the final component of the
name, not the entire path. The <b>-F</b>, <b>-w</b>, and <b>-x</b> options do not file name, not the entire path. The <b>-F</b>, <b>-w</b>, and <b>-x</b> options do
apply to this pattern. The option may be given any number of times in order to not apply to this pattern. The option may be given any number of times in order
specify multiple patterns. If a file name matches both an <b>--include</b> 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 and an <b>--exclude</b> pattern, it is excluded. There is no short form for this
option. option.
</P> </P>
@ -323,7 +330,7 @@ alternatives in the description of <b>-e</b> above.
<br> <br>
<br> <br>
If this option is given more than once, all the specified files are 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 read. A data line is output if any of the patterns match it. A file name can
be given as "-" to refer to the standard input. When <b>-f</b> is used, patterns 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 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 tested before the file's patterns. However, no other pattern is taken from the
@ -334,7 +341,7 @@ command line; all arguments are treated as the names of paths to be searched.
Read a list of files and/or directories that are to be scanned from the given 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 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 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. command line. The file name 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 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 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 which further lines (the list of files) can be read after an end-of-file
@ -352,17 +359,18 @@ and <b>--only-matching</b>.
</P> </P>
<P> <P>
<b>-H</b>, <b>--with-filename</b> <b>-H</b>, <b>--with-filename</b>
Force the inclusion of the filename at the start of output lines when searching Force the inclusion of the file name at the start of output lines when
a single file. By default, the filename is not shown in this case. For matching searching a single file. By default, the file name is not shown in this case.
lines, the filename is followed by a colon; for context lines, a hyphen For matching lines, the file name is followed by a colon; for context lines, a
separator is used. If a line number is also being output, it follows the file hyphen separator is used. If a line number is also being output, it follows the
name. file name. When the <b>-M</b> option causes a pattern to match more than one
line, only the first is preceded by the file name.
</P> </P>
<P> <P>
<b>-h</b>, <b>--no-filename</b> <b>-h</b>, <b>--no-filename</b>
Suppress the output filenames when searching multiple files. By default, Suppress the output file names when searching multiple files. By default,
filenames are shown when multiple files are searched. For matching lines, the file names 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. file name 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. If a line number is also being output, it follows the file name.
</P> </P>
<P> <P>
@ -373,7 +381,7 @@ ignored.
</P> </P>
<P> <P>
<b>-I</b> <b>-I</b>
Treat binary files as never matching. This is equivalent to Ignore binary files. This is equivalent to
<b>--binary-files</b>=<i>without-match</i>. <b>--binary-files</b>=<i>without-match</i>.
</P> </P>
<P> <P>
@ -406,8 +414,8 @@ 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 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 <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 on the command line, obtained from <b>--file-list</b>, or by scanning a parent
directory. The pattern is a PCRE2 regular expression, and is matched against the directory. The pattern is a PCRE2 regular expression, and is matched against
final component of the directory name, not the entire path. The <b>-F</b>, 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 <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 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. <b>--exclude-dir</b>, it is excluded. There is no short form for this option.
@ -442,8 +450,8 @@ unless <b>pcre2grep</b> can determine that it is reading from a terminal (which
is currently possible only in Unix-like environments). Output to terminal is is currently possible only in Unix-like environments). Output to terminal is
normally automatically flushed by the operating system. This option can be 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 useful when the input or output is attached to a pipe and you do not want
<b>pcre2grep</b> to buffer up large amounts of data. However, its use will affect <b>pcre2grep</b> to buffer up large amounts of data. However, its use will
performance, and the <b>-M</b> (multiline) option ceases to work. affect performance, and the <b>-M</b> (multiline) option ceases to work.
</P> </P>
<P> <P>
<b>--line-offsets</b> <b>--line-offsets</b>
@ -497,18 +505,33 @@ when the PCRE2 library is compiled, with the default default being 10 million.
Allow patterns to match more than one line. When this option is given, patterns Allow patterns to match more than one line. When this option is given, patterns
may usefully contain literal newline characters and internal occurrences of ^ may usefully contain literal newline characters and internal occurrences of ^
and $ characters. The output for a successful match may consist of more than 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 one line. The first is the line in which the match started, and the last is the
string ends with a newline sequence the output ends at the end of that line. line 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>
<br> <br>
When this option is set, the PCRE2 library is called in "multiline" mode. When this option is set, the PCRE2 library is called in "multiline" mode.
However, <b>pcre2grep</b> still processes the input line by line. The difference
is that a matched string may extend past the end of a line and continue on
one or more subsequent lines. The newline sequence must be matched as part of
the pattern. For example, to find the phrase "regular expression" in a file
where "regular" might be at the end of a line and "expression" at the start of
the next line, you could use this command:
<pre>
pcre2grep -M 'regular\s+expression' &#60;file&#62;
</pre>
The \s escape sequence matches any white space character, including newlines,
and is followed by + so as to match trailing white space on the first line as
well as possibly handling a two-character newline sequence.
<br>
<br>
There is a limit to the number of lines that can be matched, imposed by the way There is a limit to the number of lines that can be matched, imposed by the way
that <b>pcre2grep</b> buffers the input file as it scans it. However, that <b>pcre2grep</b> buffers the input file as it scans it. However,
<b>pcre2grep</b> ensures that at least 8K characters or the rest of the document <b>pcre2grep</b> ensures that at least 8K characters or the rest of the file
(whichever is the shorter) are available for forward matching, and similarly (whichever is the shorter) are available for forward matching, and similarly
the previous 8K characters (or all the previous characters, if fewer than 8K) 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 are guaranteed to be available for lookbehind assertions. The <b>-M</b> option
work when input is read line by line (see \fP--line-buffered\fP.) does not work when input is read line by line (see \fP--line-buffered\fP.)
</P> </P>
<P> <P>
<b>-N</b> <i>newline-type</i>, <b>--newline</b>=<i>newline-type</i> <b>-N</b> <i>newline-type</i>, <b>--newline</b>=<i>newline-type</i>
@ -526,9 +549,9 @@ When the PCRE2 library is built, a default line-ending sequence is specified.
This is normally the standard sequence for the operating system. Unless This is normally the standard sequence for the operating system. Unless
otherwise specified by this option, <b>pcre2grep</b> uses the library's default. otherwise specified by this option, <b>pcre2grep</b> uses the library's default.
The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
makes it possible to use <b>pcre2grep</b> to scan files that have come from other makes it possible to use <b>pcre2grep</b> to scan files that have come from
environments without having to modify their line endings. If the data that is other environments without having to modify their line endings. If the data
being scanned does not agree with the convention set by this option, that is being scanned does not agree with the convention set by this option,
<b>pcre2grep</b> may behave in strange ways. Note that this option does not <b>pcre2grep</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 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 <b>--include-from</b> options, which are expected to use the operating system's
@ -537,9 +560,10 @@ standard newline sequence.
<P> <P>
<b>-n</b>, <b>--line-number</b> <b>-n</b>, <b>--line-number</b>
Precede each output line by its line number in the file, followed by a colon 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 for matching lines or a hyphen for context lines. If the file name is also
output, it precedes the line number. This option is forced if being output, it precedes the line number. When the <b>-M</b> option causes a
<b>--line-offsets</b> is used. pattern to match more than one line, only the first is preceded by its line
number. This option is forced if <b>--line-offsets</b> is used.
</P> </P>
<P> <P>
<b>--no-jit</b> <b>--no-jit</b>
@ -570,7 +594,7 @@ 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 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 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 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. match, nothing is output unless the file name or line number are being output.
<br> <br>
<br> <br>
If this option is given multiple times, multiple substrings are output, in the If this option is given multiple times, multiple substrings are output, in the
@ -635,10 +659,10 @@ specified by any of the <b>--include</b> or <b>--exclude</b> options.
<b>-x</b>, <b>--line-regex</b>, <b>--line-regexp</b> <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 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 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 to having ^ and $ characters at the start and end of each alternative top-level
every pattern. This option applies only to the patterns that are matched branch in every pattern. This option applies only to the patterns that are
against the contents of files; it does not apply to patterns specified by any matched against the contents of files; it does not apply to patterns specified
of the <b>--include</b> or <b>--exclude</b> options. by any of the <b>--include</b> or <b>--exclude</b> options.
</P> </P>
<br><a name="SEC6" href="#TOC1">ENVIRONMENT VARIABLES</a><br> <br><a name="SEC6" href="#TOC1">ENVIRONMENT VARIABLES</a><br>
<P> <P>
@ -677,7 +701,7 @@ Although most of the common options work the same way, a few are different in
<b>pcre2grep</b>. For example, the <b>--include</b> option's argument is a glob <b>pcre2grep</b>. For example, the <b>--include</b> option's argument is a glob
for GNU <b>grep</b>, but a regular expression for <b>pcre2grep</b>. If both the for GNU <b>grep</b>, but a regular expression for <b>pcre2grep</b>. If both the
<b>-c</b> and <b>-l</b> options are given, GNU grep lists only file names, <b>-c</b> and <b>-l</b> options are given, GNU grep lists only file names,
without counts, but <b>pcre2grep</b> gives the counts. without counts, but <b>pcre2grep</b> gives the counts as well.
</P> </P>
<br><a name="SEC9" href="#TOC1">OPTIONS WITH DATA</a><br> <br><a name="SEC9" href="#TOC1">OPTIONS WITH DATA</a><br>
<P> <P>
@ -722,9 +746,9 @@ message and the line that caused the problem to the standard error stream. If
there are more than 20 such errors, <b>pcre2grep</b> gives up. there are more than 20 such errors, <b>pcre2grep</b> gives up.
</P> </P>
<P> <P>
The <b>--match-limit</b> option of <b>pcre2grep</b> can be used to set the overall The <b>--match-limit</b> option of <b>pcre2grep</b> can be used to set the
resource limit; there is a second option called <b>--recursion-limit</b> that overall resource limit; there is a second option called <b>--recursion-limit</b>
sets a limit on the amount of memory (usually stack) that is used (see the that sets a limit on the amount of memory (usually stack) that is used (see the
discussion of these options above). discussion of these options above).
</P> </P>
<br><a name="SEC11" href="#TOC1">DIAGNOSTICS</a><br> <br><a name="SEC11" href="#TOC1">DIAGNOSTICS</a><br>
@ -737,7 +761,7 @@ affect the return code.
</P> </P>
<br><a name="SEC12" href="#TOC1">SEE ALSO</a><br> <br><a name="SEC12" href="#TOC1">SEE ALSO</a><br>
<P> <P>
<b>pcre2pattern</b>(3), <b>pcre2syntax</b>(3), <b>pcre2test</b>(1). <b>pcre2pattern</b>(3), <b>pcre2syntax</b>(3).
</P> </P>
<br><a name="SEC13" href="#TOC1">AUTHOR</a><br> <br><a name="SEC13" href="#TOC1">AUTHOR</a><br>
<P> <P>
@ -750,9 +774,9 @@ Cambridge, England.
</P> </P>
<br><a name="SEC14" href="#TOC1">REVISION</a><br> <br><a name="SEC14" href="#TOC1">REVISION</a><br>
<P> <P>
Last updated: 23 November 2014 Last updated: 03 January 2015
<br> <br>
Copyright &copy; 1997-2014 University of Cambridge. Copyright &copy; 1997-2015 University of Cambridge.
<br> <br>
<p> <p>
Return to the <a href="index.html">PCRE2 index page</a>. Return to the <a href="index.html">PCRE2 index page</a>.

146
doc/pcre2grep.1
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@ -1,4 +1,4 @@
.TH PCRE2GREP 1 "23 November 2014" "PCRE2 10.00" .TH PCRE2GREP 1 "03 January 2015" "PCRE2 10.00"
.SH NAME .SH NAME
pcre2grep - a grep with Perl-compatible regular expressions. pcre2grep - a grep with Perl-compatible regular expressions.
.SH SYNOPSIS .SH SYNOPSIS
@ -41,21 +41,22 @@ If no files are specified, \fBpcre2grep\fP reads the standard input. The
standard input can also be referenced by a name consisting of a single hyphen. standard input can also be referenced by a name consisting of a single hyphen.
For example: For example:
.sp .sp
pcre2grep some-pattern /file1 - /file3 pcre2grep some-pattern file1 - file3
.sp .sp
By default, each line that matches a pattern is copied to the standard Input files are searched line by line. By default, each line that matches a
output, and if there is more than one file, the file name is output at the pattern is copied to the standard output, and if there is more than one file,
start of each line, followed by a colon. However, there are options that can the file name is output at the start of each line, followed by a colon.
change how \fBpcre2grep\fP behaves. In particular, the \fB-M\fP option makes it However, there are options that can change how \fBpcre2grep\fP behaves. In
possible to search for patterns that span line boundaries. What defines a line particular, the \fB-M\fP option makes it possible to search for strings that
boundary is controlled by the \fB-N\fP (\fB--newline\fP) option. span line boundaries. What defines a line boundary is controlled by the
\fB-N\fP (\fB--newline\fP) option.
.P .P
The amount of memory used for buffering files that are being scanned is 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. controlled by a parameter that can be set by the \fB--buffer-size\fP option.
The default value for this parameter is specified when \fBpcre2grep\fP is built, The default value for this parameter is specified when \fBpcre2grep\fP is
with the default default being 20K. A block of memory three times this size is built, with the default default being 20K. A block of memory three times this
used (to allow for buffering "before" and "after" lines). An error occurs if a size is used (to allow for buffering "before" and "after" lines). An error
line overflows the buffer. occurs if a line overflows the buffer.
.P .P
Patterns can be no longer than 8K or BUFSIZ bytes, whichever is the greater. 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 BUFSIZ is defined in \fB<stdio.h>\fP. When there is more than one pattern
@ -122,10 +123,10 @@ to signify multiplication by 1024 or 1024*1024 respectively.
\fB--\fP \fB--\fP
This terminates the list of options. It is useful if the next item on the 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 command line starts with a hyphen but is not an option. This allows for the
processing of patterns and filenames that start with hyphens. processing of patterns and file names that start with hyphens.
.TP .TP
\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP \fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
Output \fInumber\fP lines of context after each matching line. If filenames Output \fInumber\fP lines of context after each matching line. If file names
and/or line numbers are being output, a hyphen separator is used instead of a 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 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 group of lines, unless they are in fact contiguous in the input file. The value
@ -137,7 +138,7 @@ Treat binary files as text. This is equivalent to
\fB--binary-files\fP=\fItext\fP. \fB--binary-files\fP=\fItext\fP.
.TP .TP
\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP \fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
Output \fInumber\fP lines of context before each matching line. If filenames Output \fInumber\fP lines of context before each matching line. If file names
and/or line numbers are being output, a hyphen separator is used instead of a 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 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 group of lines, unless they are in fact contiguous in the input file. The value
@ -153,7 +154,8 @@ 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 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 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 \fB-I\fP option, binary files are not processed at all; they are assumed not to
be of interest. be of interest and are skipped without causing any output or affecting the
return code.
.TP .TP
\fB--buffer-size=\fP\fInumber\fP \fB--buffer-size=\fP\fInumber\fP
Set the parameter that controls how much memory is used for buffering files Set the parameter that controls how much memory is used for buffering files
@ -164,10 +166,14 @@ 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. This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
.TP .TP
\fB-c\fP, \fB--count\fP \fB-c\fP, \fB--count\fP
Do not output individual lines from the files that are being scanned; instead Do not output lines from the files that are being scanned; instead output the
output the number of lines that would otherwise have been shown. If no lines number of matches (or non-matches if \fB-v\fP is used) that would otherwise
are selected, the number zero is output. If several files are are being have caused lines to be shown. By default, this count is the same as the number
scanned, a count is output for each of them. However, if the of suppressed lines, but if the \fB-M\fP (multiline) option is used (without
\fB-v\fP), there may be more suppressed lines than the number of matches.
.sp
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 \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, 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. \fB-B\fP, and \fB-C\fP options are ignored.
@ -229,10 +235,10 @@ of the line that matched.
Files (but not directories) whose names match the pattern are skipped without 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, 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 obtained from \fB--file-list\fP, or by scanning a directory. The pattern is a
PCRE2 regular expression, and is matched against the final component of the file PCRE2 regular expression, and is matched against the final component of the
name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do not file name, not the entire path. The \fB-F\fP, \fB-w\fP, and \fB-x\fP options do
apply to this pattern. The option may be given any number of times in order to not apply to this pattern. The option may be given any number of times in order
specify multiple patterns. If a file name matches both an \fB--include\fP 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 and an \fB--exclude\fP pattern, it is excluded. There is no short form for this
option. option.
.TP .TP
@ -276,7 +282,7 @@ also the comments about multiple patterns versus a single pattern with
alternatives in the description of \fB-e\fP above. alternatives in the description of \fB-e\fP above.
.sp .sp
If this option is given more than once, all the specified files are 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 read. A data line is output if any of the patterns match it. A file name can
be given as "-" to refer to the standard input. When \fB-f\fP is used, patterns 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 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 tested before the file's patterns. However, no other pattern is taken from the
@ -286,7 +292,7 @@ command line; all arguments are treated as the names of paths to be searched.
Read a list of files and/or directories that are to be scanned from the given 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 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 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. command line. The file name 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 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 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 which further lines (the list of files) can be read after an end-of-file
@ -302,16 +308,17 @@ shown separately. This option is mutually exclusive with \fB--line-offsets\fP
and \fB--only-matching\fP. and \fB--only-matching\fP.
.TP .TP
\fB-H\fP, \fB--with-filename\fP \fB-H\fP, \fB--with-filename\fP
Force the inclusion of the filename at the start of output lines when searching Force the inclusion of the file name at the start of output lines when
a single file. By default, the filename is not shown in this case. For matching searching a single file. By default, the file name is not shown in this case.
lines, the filename is followed by a colon; for context lines, a hyphen For matching lines, the file name is followed by a colon; for context lines, a
separator is used. If a line number is also being output, it follows the file hyphen separator is used. If a line number is also being output, it follows the
name. file name. When the \fB-M\fP option causes a pattern to match more than one
line, only the first is preceded by the file name.
.TP .TP
\fB-h\fP, \fB--no-filename\fP \fB-h\fP, \fB--no-filename\fP
Suppress the output filenames when searching multiple files. By default, Suppress the output file names when searching multiple files. By default,
filenames are shown when multiple files are searched. For matching lines, the file names 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. file name 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. If a line number is also being output, it follows the file name.
.TP .TP
\fB--help\fP \fB--help\fP
@ -320,7 +327,7 @@ type support, and then exit. Anything else on the command line is
ignored. ignored.
.TP .TP
\fB-I\fP \fB-I\fP
Treat binary files as never matching. This is equivalent to Ignore binary files. This is equivalent to
\fB--binary-files\fP=\fIwithout-match\fP. \fB--binary-files\fP=\fIwithout-match\fP.
.TP .TP
\fB-i\fP, \fB--ignore-case\fP \fB-i\fP, \fB--ignore-case\fP
@ -349,8 +356,8 @@ 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 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 \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 on the command line, obtained from \fB--file-list\fP, or by scanning a parent
directory. The pattern is a PCRE2 regular expression, and is matched against the directory. The pattern is a PCRE2 regular expression, and is matched against
final component of the directory name, not the entire path. The \fB-F\fP, 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 \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 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. \fB--exclude-dir\fP, it is excluded. There is no short form for this option.
@ -381,8 +388,8 @@ unless \fBpcre2grep\fP can determine that it is reading from a terminal (which
is currently possible only in Unix-like environments). Output to terminal is is currently possible only in Unix-like environments). Output to terminal is
normally automatically flushed by the operating system. This option can be 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 useful when the input or output is attached to a pipe and you do not want
\fBpcre2grep\fP to buffer up large amounts of data. However, its use will affect \fBpcre2grep\fP to buffer up large amounts of data. However, its use will
performance, and the \fB-M\fP (multiline) option ceases to work. affect performance, and the \fB-M\fP (multiline) option ceases to work.
.TP .TP
\fB--line-offsets\fP \fB--line-offsets\fP
Instead of showing lines or parts of lines that match, show each match as a Instead of showing lines or parts of lines that match, show each match as a
@ -429,17 +436,31 @@ when the PCRE2 library is compiled, with the default default being 10 million.
Allow patterns to match more than one line. When this option is given, patterns Allow patterns to match more than one line. When this option is given, patterns
may usefully contain literal newline characters and internal occurrences of ^ may usefully contain literal newline characters and internal occurrences of ^
and $ characters. The output for a successful match may consist of more than 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 one line. The first is the line in which the match started, and the last is the
string ends with a newline sequence the output ends at the end of that line. line in which the match ended. If the matched string ends with a newline
sequence the output ends at the end of that line.
.sp .sp
When this option is set, the PCRE2 library is called in "multiline" mode. When this option is set, the PCRE2 library is called in "multiline" mode.
However, \fBpcre2grep\fP still processes the input line by line. The difference
is that a matched string may extend past the end of a line and continue on
one or more subsequent lines. The newline sequence must be matched as part of
the pattern. For example, to find the phrase "regular expression" in a file
where "regular" might be at the end of a line and "expression" at the start of
the next line, you could use this command:
.sp
pcre2grep -M 'regular\es+expression' <file>
.sp
The \es escape sequence matches any white space character, including newlines,
and is followed by + so as to match trailing white space on the first line as
well as possibly handling a two-character newline sequence.
.sp
There is a limit to the number of lines that can be matched, imposed by the way There is a limit to the number of lines that can be matched, imposed by the way
that \fBpcre2grep\fP buffers the input file as it scans it. However, that \fBpcre2grep\fP buffers the input file as it scans it. However,
\fBpcre2grep\fP ensures that at least 8K characters or the rest of the document \fBpcre2grep\fP ensures that at least 8K characters or the rest of the file
(whichever is the shorter) are available for forward matching, and similarly (whichever is the shorter) are available for forward matching, and similarly
the previous 8K characters (or all the previous characters, if fewer than 8K) 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 are guaranteed to be available for lookbehind assertions. The \fB-M\fP option
work when input is read line by line (see \fP--line-buffered\fP.) does not work when input is read line by line (see \fP--line-buffered\fP.)
.TP .TP
\fB-N\fP \fInewline-type\fP, \fB--newline\fP=\fInewline-type\fP \fB-N\fP \fInewline-type\fP, \fB--newline\fP=\fInewline-type\fP
The PCRE2 library supports five different conventions for indicating The PCRE2 library supports five different conventions for indicating
@ -455,9 +476,9 @@ When the PCRE2 library is built, a default line-ending sequence is specified.
This is normally the standard sequence for the operating system. Unless This is normally the standard sequence for the operating system. Unless
otherwise specified by this option, \fBpcre2grep\fP uses the library's default. otherwise specified by this option, \fBpcre2grep\fP uses the library's default.
The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
makes it possible to use \fBpcre2grep\fP to scan files that have come from other makes it possible to use \fBpcre2grep\fP to scan files that have come from
environments without having to modify their line endings. If the data that is other environments without having to modify their line endings. If the data
being scanned does not agree with the convention set by this option, that is being scanned does not agree with the convention set by this option,
\fBpcre2grep\fP may behave in strange ways. Note that this option does not \fBpcre2grep\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 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 \fB--include-from\fP options, which are expected to use the operating system's
@ -465,9 +486,10 @@ standard newline sequence.
.TP .TP
\fB-n\fP, \fB--line-number\fP \fB-n\fP, \fB--line-number\fP
Precede each output line by its line number in the file, followed by a colon 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 for matching lines or a hyphen for context lines. If the file name is also
output, it precedes the line number. This option is forced if being output, it precedes the line number. When the \fB-M\fP option causes a
\fB--line-offsets\fP is used. pattern to match more than one line, only the first is preceded by its line
number. This option is forced if \fB--line-offsets\fP is used.
.TP .TP
\fB--no-jit\fP \fB--no-jit\fP
If the PCRE2 library is built with support for just-in-time compiling (which If the PCRE2 library is built with support for just-in-time compiling (which
@ -495,7 +517,7 @@ 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 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 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 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. match, nothing is output unless the file name or line number are being output.
.sp .sp
If this option is given multiple times, multiple substrings are output, in the 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 order the options are given. For example, -o3 -o1 -o3 causes the substrings
@ -549,10 +571,10 @@ specified by any of the \fB--include\fP or \fB--exclude\fP options.
\fB-x\fP, \fB--line-regex\fP, \fB--line-regexp\fP \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 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 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 to having ^ and $ characters at the start and end of each alternative top-level
every pattern. This option applies only to the patterns that are matched branch in every pattern. This option applies only to the patterns that are
against the contents of files; it does not apply to patterns specified by any matched against the contents of files; it does not apply to patterns specified
of the \fB--include\fP or \fB--exclude\fP options. by any of the \fB--include\fP or \fB--exclude\fP options.
. .
. .
.SH "ENVIRONMENT VARIABLES" .SH "ENVIRONMENT VARIABLES"
@ -596,7 +618,7 @@ Although most of the common options work the same way, a few are different in
\fBpcre2grep\fP. For example, the \fB--include\fP option's argument is a glob \fBpcre2grep\fP. For example, the \fB--include\fP option's argument is a glob
for GNU \fBgrep\fP, but a regular expression for \fBpcre2grep\fP. If both the for GNU \fBgrep\fP, but a regular expression for \fBpcre2grep\fP. If both the
\fB-c\fP and \fB-l\fP options are given, GNU grep lists only file names, \fB-c\fP and \fB-l\fP options are given, GNU grep lists only file names,
without counts, but \fBpcre2grep\fP gives the counts. without counts, but \fBpcre2grep\fP gives the counts as well.
. .
. .
.SH "OPTIONS WITH DATA" .SH "OPTIONS WITH DATA"
@ -642,9 +664,9 @@ in these circumstances. If this happens, \fBpcre2grep\fP outputs an error
message and the line that caused the problem to the standard error stream. If message and the line that caused the problem to the standard error stream. If
there are more than 20 such errors, \fBpcre2grep\fP gives up. there are more than 20 such errors, \fBpcre2grep\fP gives up.
.P .P
The \fB--match-limit\fP option of \fBpcre2grep\fP can be used to set the overall The \fB--match-limit\fP option of \fBpcre2grep\fP can be used to set the
resource limit; there is a second option called \fB--recursion-limit\fP that overall resource limit; there is a second option called \fB--recursion-limit\fP
sets a limit on the amount of memory (usually stack) that is used (see the that sets a limit on the amount of memory (usually stack) that is used (see the
discussion of these options above). discussion of these options above).
. .
. .
@ -661,7 +683,7 @@ affect the return code.
.SH "SEE ALSO" .SH "SEE ALSO"
.rs .rs
.sp .sp
\fBpcre2pattern\fP(3), \fBpcre2syntax\fP(3), \fBpcre2test\fP(1). \fBpcre2pattern\fP(3), \fBpcre2syntax\fP(3).
. .
. .
.SH AUTHOR .SH AUTHOR
@ -678,6 +700,6 @@ Cambridge, England.
.rs .rs
.sp .sp
.nf .nf
Last updated: 23 November 2014 Last updated: 03 January 2015
Copyright (c) 1997-2014 University of Cambridge. Copyright (c) 1997-2015 University of Cambridge.
.fi .fi

444
doc/pcre2grep.txt
View File

@ -40,15 +40,15 @@ DESCRIPTION
standard input can also be referenced by a name consisting of a single standard input can also be referenced by a name consisting of a single
hyphen. For example: hyphen. For example:
pcre2grep some-pattern /file1 - /file3 pcre2grep some-pattern file1 - file3
By default, each line that matches a pattern is copied to the standard Input files are searched line by line. By default, each line that
output, and if there is more than one file, the file name is output at matches a pattern is copied to the standard output, and if there is
the start of each line, followed by a colon. However, there are options more than one file, the file name is output at the start of each line,
that can change how pcre2grep behaves. In particular, the -M option followed by a colon. However, there are options that can change how
makes it possible to search for patterns that span line boundaries. pcre2grep behaves. In particular, the -M option makes it possible to
What defines a line boundary is controlled by the -N (--newline) search for strings that span line boundaries. What defines a line
option. boundary is controlled by the -N (--newline) option.
The amount of memory used for buffering files that are being scanned is 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. controlled by a parameter that can be set by the --buffer-size option.
@ -122,13 +122,13 @@ OPTIONS
-- This terminates the list of options. It is useful if the next -- 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 item on the command line starts with a hyphen but is not an
option. This allows for the processing of patterns and file- option. This allows for the processing of patterns and file
names that start with hyphens. names that start with hyphens.
-A number, --after-context=number -A number, --after-context=number
Output number lines of context after each matching line. If Output number lines of context after each matching line. If
filenames and/or line numbers are being output, a hyphen sep- file names and/or line numbers are being output, a hyphen
arator is used instead of a colon for the context lines. A separator is used instead of a colon for the context lines. A
line containing "--" is output between each group of lines, line containing "--" is output between each group of lines,
unless they are in fact contiguous in the input file. The unless they are in fact contiguous in the input file. The
value of number is expected to be relatively small. However, value of number is expected to be relatively small. However,
@ -141,8 +141,8 @@ OPTIONS
-B number, --before-context=number -B number, --before-context=number
Output number lines of context before each matching line. If Output number lines of context before each matching line. If
filenames and/or line numbers are being output, a hyphen sep- file names and/or line numbers are being output, a hyphen
arator is used instead of a colon for the context lines. A separator is used instead of a colon for the context lines. A
line containing "--" is output between each group of lines, line containing "--" is output between each group of lines,
unless they are in fact contiguous in the input file. The unless they are in fact contiguous in the input file. The
value of number is expected to be relatively small. However, value of number is expected to be relatively small. However,
@ -160,249 +160,258 @@ OPTIONS
which can have nasty effects if sent to a terminal. If the which can have nasty effects if sent to a terminal. If the
word is "without-match", which is equivalent to the -I word is "without-match", which is equivalent to the -I
option, binary files are not processed at all; they are option, binary files are not processed at all; they are
assumed not to be of interest. assumed not to be of interest and are skipped without causing
any output or affecting the return code.
--buffer-size=number --buffer-size=number
Set the parameter that controls how much memory is used for Set the parameter that controls how much memory is used for
buffering files that are being scanned. buffering files that are being scanned.
-C number, --context=number -C number, --context=number
Output number lines of context both before and after each Output number lines of context both before and after each
matching line. This is equivalent to setting both -A and -B matching line. This is equivalent to setting both -A and -B
to the same value. to the same value.
-c, --count -c, --count
Do not output individual lines from the files that are being Do not output lines from the files that are being scanned;
scanned; instead output the number of lines that would other- instead output the number of matches (or non-matches if -v is
wise have been shown. If no lines are selected, the number used) that would otherwise have caused lines to be shown. By
zero is output. If several files are are being scanned, a default, this count is the same as the number of suppressed
count is output for each of them. However, if the --files- lines, but if the -M (multiline) option is used (without -v),
with-matches option is also used, only those files whose there may be more suppressed lines than the number of
counts are greater than zero are listed. When -c is used, the matches.
-A, -B, and -C options are ignored.
If no lines are selected, the number zero is output. If sev-
eral 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 --colour, --color
If this option is given without any data, it is equivalent to If this option is given without any data, it is equivalent to
"--colour=auto". If data is required, it must be given in "--colour=auto". If data is required, it must be given in
the same shell item, separated by an equals sign. the same shell item, separated by an equals sign.
--colour=value, --color=value --colour=value, --color=value
This option specifies under what circumstances the parts of a This option specifies under what circumstances the parts of a
line that matched a pattern should be coloured in the output. line that matched a pattern should be coloured in the output.
By default, the output is not coloured. The value (which is By default, the output is not coloured. The value (which is
optional, see above) may be "never", "always", or "auto". In optional, see above) may be "never", "always", or "auto". In
the latter case, colouring happens only if the standard out- the latter case, colouring happens only if the standard out-
put is connected to a terminal. More resources are used when put is connected to a terminal. More resources are used when
colouring is enabled, because pcre2grep has to search for all colouring is enabled, because pcre2grep has to search for all
possible matches in a line, not just one, in order to colour possible matches in a line, not just one, in order to colour
them all. them all.
The colour that is used can be specified by setting the envi- The colour that is used can be specified by setting the envi-
ronment variable PCRE2GREP_COLOUR or PCRE2GREP_COLOR. The ronment variable PCRE2GREP_COLOUR or PCRE2GREP_COLOR. The
value of this variable should be a string of two numbers, value of this variable should be a string of two numbers,
separated by a semicolon. They are copied directly into the separated by a semicolon. They are copied directly into the
control string for setting colour on a terminal, so it is control string for setting colour on a terminal, so it is
your responsibility to ensure that they make sense. If nei- your responsibility to ensure that they make sense. If nei-
ther of the environment variables is set, the default is ther of the environment variables is set, the default is
"1;31", which gives red. "1;31", which gives red.
-D action, --devices=action -D action, --devices=action
If an input path is not a regular file or a directory, If an input path is not a regular file or a directory,
"action" specifies how it is to be processed. Valid values "action" specifies how it is to be processed. Valid values
are "read" (the default) or "skip" (silently skip the path). are "read" (the default) or "skip" (silently skip the path).
-d action, --directories=action -d action, --directories=action
If an input path is a directory, "action" specifies how it is If an input path is a directory, "action" specifies how it is
to be processed. Valid values are "read" (the default in to be processed. Valid values are "read" (the default in
non-Windows environments, for compatibility with GNU grep), non-Windows environments, for compatibility with GNU grep),
"recurse" (equivalent to the -r option), or "skip" (silently "recurse" (equivalent to the -r option), or "skip" (silently
skip the path, the default in Windows environments). In the skip the path, the default in Windows environments). In the
"read" case, directories are read as if they were ordinary "read" case, directories are read as if they were ordinary
files. In some operating systems the effect of reading a files. In some operating systems the effect of reading a
directory like this is an immediate end-of-file; in others it directory like this is an immediate end-of-file; in others it
may provoke an error. may provoke an error.
-e pattern, --regex=pattern, --regexp=pattern -e pattern, --regex=pattern, --regexp=pattern
Specify a pattern to be matched. This option can be used mul- Specify a pattern to be matched. This option can be used mul-
tiple times in order to specify several patterns. It can also tiple times in order to specify several patterns. It can also
be used as a way of specifying a single pattern that starts be used as a way of specifying a single pattern that starts
with a hyphen. When -e is used, no argument pattern is taken with a hyphen. When -e is used, no argument pattern is taken
from the command line; all arguments are treated as file from the command line; all arguments are treated as file
names. There is no limit to the number of patterns. They are names. There is no limit to the number of patterns. They are
applied to each line in the order in which they are defined applied to each line in the order in which they are defined
until one matches. until one matches.
If -f is used with -e, the command line patterns are matched If -f is used with -e, the command line patterns are matched
first, followed by the patterns from the file(s), independent first, followed by the patterns from the file(s), independent
of the order in which these options are specified. Note that of the order in which these options are specified. Note that
multiple use of -e is not the same as a single pattern with multiple use of -e is not the same as a single pattern with
alternatives. For example, X|Y finds the first character in a alternatives. For example, X|Y finds the first character in a
line that is X or Y, whereas if the two patterns are given line that is X or Y, whereas if the two patterns are given
separately, with X first, pcre2grep finds X if it is present, separately, with X first, pcre2grep finds X if it is present,
even if it follows Y in the line. It finds Y only if there is 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 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. --colo(u)r to show the part(s) of the line that matched.
--exclude=pattern --exclude=pattern
Files (but not directories) whose names match the pattern are Files (but not directories) whose names match the pattern are
skipped without being processed. This applies to all files, skipped without being processed. This applies to all files,
whether listed on the command line, obtained from --file- whether listed on the command line, obtained from --file-
list, or by scanning a directory. The pattern is a PCRE2 reg- list, or by scanning a directory. The pattern is a PCRE2 reg-
ular expression, and is matched against the final component ular expression, and is matched against the final component
of the file name, not the entire path. The -F, -w, and -x 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 options do not apply to this pattern. The option may be given
any number of times in order to specify multiple patterns. If any number of times in order to specify multiple patterns. If
a file name matches both an --include and an --exclude pat- a file name matches both an --include and an --exclude pat-
tern, it is excluded. There is no short form for this option. tern, it is excluded. There is no short form for this option.
--exclude-from=filename --exclude-from=filename
Treat each non-empty line of the file as the data for an Treat each non-empty line of the file as the data for an
--exclude option. What constitutes a newline when reading the --exclude option. What constitutes a newline when reading the
file is the operating system's default. The --newline option file is the operating system's default. The --newline option
has no effect on this option. This option may be given more has no effect on this option. This option may be given more
than once in order to specify a number of files to read. than once in order to specify a number of files to read.
--exclude-dir=pattern --exclude-dir=pattern
Directories whose names match the pattern are skipped without Directories whose names match the pattern are skipped without
being processed, whatever the setting of the --recursive being processed, whatever the setting of the --recursive
option. This applies to all directories, whether listed on option. This applies to all directories, whether listed on
the command line, obtained from --file-list, or by scanning a the command line, obtained from --file-list, or by scanning a
parent directory. The pattern is a PCRE2 regular expression, parent directory. The pattern is a PCRE2 regular expression,
and is matched against the final component of the directory and is matched against the final component of the directory
name, not the entire path. The -F, -w, and -x options do not 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 apply to this pattern. The option may be given any number of
times in order to specify more than one pattern. If a direc- times in order to specify more than one pattern. If a direc-
tory matches both --include-dir and --exclude-dir, it is tory matches both --include-dir and --exclude-dir, it is
excluded. There is no short form for this option. excluded. There is no short form for this option.
-F, --fixed-strings -F, --fixed-strings
Interpret each data-matching pattern as a list of fixed Interpret each data-matching pattern as a list of fixed
strings, separated by newlines, instead of as a regular strings, separated by newlines, instead of as a regular
expression. What constitutes a newline for this purpose is expression. What constitutes a newline for this purpose is
controlled by the --newline option. The -w (match as a word) controlled by the --newline option. The -w (match as a word)
and -x (match whole line) options can be used with -F. They 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 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 of the fixed strings are found in it (subject to -w or -x, if
present). This option applies only to the patterns that are present). This option applies only to the patterns that are
matched against the contents of files; it does not apply to matched against the contents of files; it does not apply to
patterns specified by any of the --include or --exclude patterns specified by any of the --include or --exclude
options. options.
-f filename, --file=filename -f filename, --file=filename
Read patterns from the file, one per line, and match them Read patterns from the file, one per line, and match them
against each line of input. What constitutes a newline when against each line of input. What constitutes a newline when
reading the file is the operating system's default. The reading the file is the operating system's default. The
--newline option has no effect on this option. Trailing white --newline option has no effect on this option. Trailing white
space is removed from each line, and blank lines are ignored. space is removed from each line, and blank lines are ignored.
An empty file contains no patterns and therefore matches An empty file contains no patterns and therefore matches
nothing. See also the comments about multiple patterns versus nothing. See also the comments about multiple patterns versus
a single pattern with alternatives in the description of -e a single pattern with alternatives in the description of -e
above. above.
If this option is given more than once, all the specified If this option is given more than once, all the specified
files are read. A data line is output if any of the patterns 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 match it. A file name can be given as "-" to refer to the
standard input. When -f is used, patterns specified on the standard input. When -f is used, patterns specified on the
command line using -e may also be present; they are tested command line using -e may also be present; they are tested
before the file's patterns. However, no other pattern is before the file's patterns. However, no other pattern is
taken from the command line; all arguments are treated as the taken from the command line; all arguments are treated as the
names of paths to be searched. names of paths to be searched.
--file-list=filename --file-list=filename
Read a list of files and/or directories that are to be Read a list of files and/or directories that are to be
scanned from the given file, one per line. Trailing white scanned from the given file, one per line. Trailing white
space is removed from each line, and blank lines are ignored. space is removed from each line, and blank lines are ignored.
These paths are processed before any that are listed on the These paths are processed before any that are listed on the
command line. The filename can be given as "-" to refer to command line. The file name can be given as "-" to refer to
the standard input. If --file and --file-list are both spec- the standard input. If --file and --file-list are both spec-
ified as "-", patterns are read first. This is useful only ified as "-", patterns are read first. This is useful only
when the standard input is a terminal, from which further when the standard input is a terminal, from which further
lines (the list of files) can be read after an end-of-file lines (the list of files) can be read after an end-of-file
indication. If this option is given more than once, all the indication. If this option is given more than once, all the
specified files are read. specified files are read.
--file-offsets --file-offsets
Instead of showing lines or parts of lines that match, show Instead of showing lines or parts of lines that match, show
each match as an offset from the start of the file and a each match as an offset from the start of the file and a
length, separated by a comma. In this mode, no context is length, separated by a comma. In this mode, no context is
shown. That is, the -A, -B, and -C options are ignored. If 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 there is more than one match in a line, each of them is shown
separately. This option is mutually exclusive with --line- separately. This option is mutually exclusive with --line-
offsets and --only-matching. offsets and --only-matching.
-H, --with-filename -H, --with-filename
Force the inclusion of the filename at the start of output Force the inclusion of the file name at the start of output
lines when searching a single file. By default, the filename lines when searching a single file. By default, the file name
is not shown in this case. For matching lines, the filename is not shown in this case. For matching lines, the file name
is followed by a colon; for context lines, a hyphen separator is followed by a colon; for context lines, a hyphen separator
is used. If a line number is also being output, it follows is used. If a line number is also being output, it follows
the file name. the file name. When the -M option causes a pattern to match
more than one line, only the first is preceded by the file
name.
-h, --no-filename -h, --no-filename
Suppress the output filenames when searching multiple files. Suppress the output file names when searching multiple files.
By default, filenames are shown when multiple files are By default, file names are shown when multiple files are
searched. For matching lines, the filename is followed by a searched. For matching lines, the file name is followed by a
colon; for context lines, a hyphen separator is used. If a colon; for context lines, a hyphen separator is used. If a
line number is also being output, it follows the file name. line number is also being output, it follows the file name.
--help Output a help message, giving brief details of the command --help Output a help message, giving brief details of the command
options and file type support, and then exit. Anything else options and file type support, and then exit. Anything else
on the command line is ignored. on the command line is ignored.
-I Treat binary files as never matching. This is equivalent to -I Ignore binary files. This is equivalent to --binary-
--binary-files=without-match. files=without-match.
-i, --ignore-case -i, --ignore-case
Ignore upper/lower case distinctions during comparisons. Ignore upper/lower case distinctions during comparisons.
--include=pattern --include=pattern
If any --include patterns are specified, the only files that If any --include patterns are specified, the only files that
are processed are those that match one of the patterns (and are processed are those that match one of the patterns (and
do not match an --exclude pattern). This option does not do not match an --exclude pattern). This option does not
affect directories, but it applies to all files, whether affect directories, but it applies to all files, whether
listed on the command line, obtained from --file-list, or by listed on the command line, obtained from --file-list, or by
scanning a directory. The pattern is a PCRE2 regular expres- scanning a directory. The pattern is a PCRE2 regular expres-
sion, and is matched against the final component of the file sion, and is matched against the final component of the file
name, not the entire path. The -F, -w, and -x options do not 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 apply to this pattern. The option may be given any number of
times. If a file name matches both an --include and an times. If a file name matches both an --include and an
--exclude pattern, it is excluded. There is no short form --exclude pattern, it is excluded. There is no short form
for this option. for this option.
--include-from=filename --include-from=filename
Treat each non-empty line of the file as the data for an Treat each non-empty line of the file as the data for an
--include option. What constitutes a newline for this purpose --include option. What constitutes a newline for this purpose
is the operating system's default. The --newline option has is the operating system's default. The --newline option has
no effect on this option. This option may be given any number no effect on this option. This option may be given any number
of times; all the files are read. of times; all the files are read.
--include-dir=pattern --include-dir=pattern
If any --include-dir patterns are specified, the only direc- If any --include-dir patterns are specified, the only direc-
tories that are processed are those that match one of the tories that are processed are those that match one of the
patterns (and do not match an --exclude-dir pattern). This patterns (and do not match an --exclude-dir pattern). This
applies to all directories, whether listed on the command applies to all directories, whether listed on the command
line, obtained from --file-list, or by scanning a parent line, obtained from --file-list, or by scanning a parent
directory. The pattern is a PCRE2 regular expression, and is directory. The pattern is a PCRE2 regular expression, and is
matched against the final component of the directory name, matched against the final component of the directory name,
not the entire path. The -F, -w, and -x options do not apply 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. to this pattern. The option may be given any number of times.
If a directory matches both --include-dir and --exclude-dir, If a directory matches both --include-dir and --exclude-dir,
it is excluded. There is no short form for this option. it is excluded. There is no short form for this option.
-L, --files-without-match -L, --files-without-match
Instead of outputting lines from the files, just output the Instead of outputting lines from the files, just output the
names of the files that do not contain any lines that would names of the files that do not contain any lines that would
have been output. Each file name is output once, on a sepa- have been output. Each file name is output once, on a sepa-
rate line. rate line.
-l, --files-with-matches -l, --files-with-matches
Instead of outputting lines from the files, just output the Instead of outputting lines from the files, just output the
names of the files containing lines that would have been out- names of the files containing lines that would have been out-
put. Each file name is output once, on a separate line. put. Each file name is output once, on a separate line.
Searching normally stops as soon as a matching line is found Searching normally stops as soon as a matching line is found
in a file. However, if the -c (count) option is also used, in a file. However, if the -c (count) option is also used,
matching continues in order to obtain the correct count, and matching continues in order to obtain the correct count, and
those files that have at least one match are listed along those files that have at least one match are listed along
with their counts. Using this option with -c is a way of sup- with their counts. Using this option with -c is a way of sup-
pressing the listing of files with no matches. pressing the listing of files with no matches.
@ -412,86 +421,103 @@ OPTIONS
input)" is used. There is no short form for this option. input)" is used. There is no short form for this option.
--line-buffered --line-buffered
When this option is given, input is read and processed line When this option is given, input is read and processed line
by line, and the output is flushed after each write. By by line, and the output is flushed after each write. By
default, input is read in large chunks, unless pcre2grep can default, input is read in large chunks, unless pcre2grep can
determine that it is reading from a terminal (which is cur- determine that it is reading from a terminal (which is cur-
rently possible only in Unix-like environments). Output to rently possible only in Unix-like environments). Output to
terminal is normally automatically flushed by the operating terminal is normally automatically flushed by the operating
system. This option can be useful when the input or output is system. This option can be useful when the input or output is
attached to a pipe and you do not want pcre2grep to buffer up attached to a pipe and you do not want pcre2grep to buffer up
large amounts of data. However, its use will affect perfor- large amounts of data. However, its use will affect perfor-
mance, and the -M (multiline) option ceases to work. mance, and the -M (multiline) option ceases to work.
--line-offsets --line-offsets
Instead of showing lines or parts of lines that match, show Instead of showing lines or parts of lines that match, show
each match as a line number, the offset from the start of the 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 line, and a length. The line number is terminated by a colon
(as usual; see the -n option), and the offset and length are (as usual; see the -n option), and the offset and length are
separated by a comma. In this mode, no context is shown. separated by a comma. In this mode, no context is shown.
That is, the -A, -B, and -C options are ignored. If there is 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 sepa- more than one match in a line, each of them is shown sepa-
rately. This option is mutually exclusive with --file-offsets rately. This option is mutually exclusive with --file-offsets
and --only-matching. and --only-matching.
--locale=locale-name --locale=locale-name
This option specifies a locale to be used for pattern match- This option specifies a locale to be used for pattern match-
ing. It overrides the value in the LC_ALL or LC_CTYPE envi- ing. It overrides the value in the LC_ALL or LC_CTYPE envi-
ronment variables. If no locale is specified, the PCRE2 ronment variables. If no locale is specified, the PCRE2
library's default (usually the "C" locale) is used. There is library's default (usually the "C" locale) is used. There is
no short form for this option. no short form for this option.
--match-limit=number --match-limit=number
Processing some regular expression patterns can require a Processing some regular expression patterns can require a
very large amount of memory, leading in some cases to a pro- very large amount of memory, leading in some cases to a pro-
gram crash if not enough is available. Other patterns may gram crash if not enough is available. Other patterns may
take a very long time to search for all possible matching take a very long time to search for all possible matching
strings. The pcre2_match() function that is called by strings. The pcre2_match() function that is called by
pcre2grep to do the matching has two parameters that can pcre2grep to do the matching has two parameters that can
limit the resources that it uses. limit the resources that it uses.
The --match-limit option provides a means of limiting The --match-limit option provides a means of limiting
resource usage when processing patterns that are not going to resource usage when processing patterns that are not going to
match, but which have a very large number of possibilities in match, but which have a very large number of possibilities in
their search trees. The classic example is a pattern that their search trees. The classic example is a pattern that
uses nested unlimited repeats. Internally, PCRE2 uses a func- uses nested unlimited repeats. Internally, PCRE2 uses a func-
tion called match() which it calls repeatedly (sometimes tion called match() which it calls repeatedly (sometimes
recursively). The limit set by --match-limit is imposed on recursively). The limit set by --match-limit is imposed on
the number of times this function is called during a match, the number of times this function is called during a match,
which has the effect of limiting the amount of backtracking which has the effect of limiting the amount of backtracking
that can take place. that can take place.
The --recursion-limit option is similar to --match-limit, but The --recursion-limit option is similar to --match-limit, but
instead of limiting the total number of times that match() is instead of limiting the total number of times that match() is
called, it limits the depth of recursive calls, which in turn called, it limits the depth of recursive calls, which in turn
limits the amount of memory that can be used. The recursion limits the amount of memory that can be used. The recursion
depth is a smaller number than the total number of calls, depth is a smaller number than the total number of calls,
because not all calls to match() are recursive. This limit is because not all calls to match() are recursive. This limit is
of use only if it is set smaller than --match-limit. of use only if it is set smaller than --match-limit.
There are no short forms for these options. The default set- There are no short forms for these options. The default set-
tings are specified when the PCRE2 library is compiled, with tings are specified when the PCRE2 library is compiled, with
the default default being 10 million. the default default being 10 million.
-M, --multiline -M, --multiline
Allow patterns to match more than one line. When this option Allow patterns to match more than one line. When this option
is given, patterns may usefully contain literal newline char- is given, patterns may usefully contain literal newline char-
acters and internal occurrences of ^ and $ characters. The acters and internal occurrences of ^ and $ characters. The
output for a successful match may consist of more than one output for a successful match may consist of more than one
line, the last of which is the one in which the match ended. line. The first is the line in which the match started, and
If the matched string ends with a newline sequence the output the last is the line in which the match ended. If the matched
ends at the end of that line. string ends with a newline sequence the output ends at the
end of that line.
When this option is set, the PCRE2 library is called in "mul- When this option is set, the PCRE2 library is called in "mul-
tiline" mode. There is a limit to the number of lines that tiline" mode. However, pcre2grep still processes the input
can be matched, imposed by the way that pcre2grep buffers the line by line. The difference is that a matched string may
input file as it scans it. However, pcre2grep ensures that at extend past the end of a line and continue on one or more
least 8K characters or the rest of the document (whichever is subsequent lines. The newline sequence must be matched as
the shorter) are available for forward matching, and simi- part of the pattern. For example, to find the phrase "regular
larly the previous 8K characters (or all the previous charac- expression" in a file where "regular" might be at the end of
ters, if fewer than 8K) are guaranteed to be available for a line and "expression" at the start of the next line, you
lookbehind assertions. This option does not work when input could use this command:
is read line by line (see --line-buffered.)
pcre2grep -M 'regular\s+expression' <file>
The \s escape sequence matches any white space character,
including newlines, and is followed by + so as to match
trailing white space on the first line as well as possibly
handling a two-character newline sequence.
There is a limit to the number of lines that can be matched,
imposed by the way that pcre2grep buffers the input file as
it scans it. However, pcre2grep ensures that at least 8K
characters or the rest of the file (whichever is the shorter)
are available for forward matching, and similarly the previ-
ous 8K characters (or all the previous characters, if fewer
than 8K) are guaranteed to be available for lookbehind asser-
tions. The -M option does not work when input is read line by
line (see --line-buffered.)
-N newline-type, --newline=newline-type -N newline-type, --newline=newline-type
The PCRE2 library supports five different conventions for The PCRE2 library supports five different conventions for
@ -522,8 +548,10 @@ OPTIONS
-n, --line-number -n, --line-number
Precede each output line by its line number in the file, fol- Precede each output line by its line number in the file, fol-
lowed by a colon for matching lines or a hyphen for context lowed by a colon for matching lines or a hyphen for context
lines. If the filename is also being output, it precedes the lines. If the file name is also being output, it precedes the
line number. This option is forced if --line-offsets is used. line number. When the -M option causes a pattern to match
more than one line, only the first is preceded by its line
number. This option is forced if --line-offsets is used.
--no-jit If the PCRE2 library is built with support for just-in-time --no-jit If the PCRE2 library is built with support for just-in-time
compiling (which speeds up matching), pcre2grep automatically compiling (which speeds up matching), pcre2grep automatically
@ -555,8 +583,8 @@ OPTIONS
The comments given for the non-argument case above also apply The comments given for the non-argument case above also apply
to this case. If the specified capturing parentheses do not to this case. If the specified capturing parentheses do not
exist in the pattern, or were not set in the match, nothing exist in the pattern, or were not set in the match, nothing
is output unless the file name or line number are being is output unless the file name or line number are being out-
printed. put.
If this option is given multiple times, multiple substrings If this option is given multiple times, multiple substrings
are output, in the order the options are given. For example, are output, in the order the options are given. For example,
@ -617,11 +645,11 @@ OPTIONS
Force the patterns to be anchored (each must start matching Force the patterns to be anchored (each must start matching
at the beginning of a line) and in addition, require them to at the beginning of a line) and in addition, require them to
match entire lines. This is equivalent to having ^ and $ match entire lines. This is equivalent to having ^ and $
characters at the start and end of each alternative branch in characters at the start and end of each alternative top-level
every pattern. This option applies only to the patterns that branch in every pattern. This option applies only to the pat-
are matched against the contents of files; it does not apply terns that are matched against the contents of files; it does
to patterns specified by any of the --include or --exclude not apply to patterns specified by any of the --include or
options. --exclude options.
ENVIRONMENT VARIABLES ENVIRONMENT VARIABLES
@ -662,7 +690,7 @@ OPTIONS COMPATIBILITY
ferent in pcre2grep. For example, the --include option's argument is a ferent in pcre2grep. For example, the --include option's argument is a
glob for GNU grep, but a regular expression for pcre2grep. If both the glob for GNU grep, but a regular expression for pcre2grep. If both the
-c and -l options are given, GNU grep lists only file names, without -c and -l options are given, GNU grep lists only file names, without
counts, but pcre2grep gives the counts. counts, but pcre2grep gives the counts as well.
OPTIONS WITH DATA OPTIONS WITH DATA
@ -725,7 +753,7 @@ DIAGNOSTICS
SEE ALSO SEE ALSO
pcre2pattern(3), pcre2syntax(3), pcre2test(1). pcre2pattern(3), pcre2syntax(3).
AUTHOR AUTHOR
@ -737,5 +765,5 @@ AUTHOR
REVISION REVISION
Last updated: 23 November 2014 Last updated: 03 January 2015
Copyright (c) 1997-2014 University of Cambridge. Copyright (c) 1997-2015 University of Cambridge.