trunk/doc/pcregrep.1

.TH PCREGREP 1
.SH NAME
pcregrep - a grep with Perl-compatible regular expressions.
.SH SYNOPSIS
.B pcregrep [options] [long options] [pattern] [path1 path2 ...]
.
.SH DESCRIPTION
.rs
.sp
\fBpcregrep\fP searches files for character patterns, in the same way as other
grep commands do, but it uses the PCRE regular expression library to support
patterns that are compatible with the regular expressions of Perl 5. See
.\" HREF
\fBpcrepattern\fP
.\"
for a full description of syntax and semantics of the regular expressions that
PCRE supports.
.P
Patterns, whether supplied on the command line or in a separate file, are given
without delimiters. For example:
.sp
  pcregrep Thursday /etc/motd
.sp
If you attempt to use delimiters (for example, by surrounding a pattern with
slashes, as is common in Perl scripts), they are interpreted as part of the
pattern. Quotes can of course be used on the command line because they are
interpreted by the shell, and indeed they are required if a pattern contains
white space or shell metacharacters.
.P
The first argument that follows any option settings is treated as the single
pattern to be matched when neither \fB-e\fP nor \fB-f\fP is present.
Conversely, when one or both of these options are used to specify patterns, all
arguments are treated as path names. At least one of \fB-e\fP, \fB-f\fP, or an
argument pattern must be provided.
.P
If no files are specified, \fBpcregrep\fP reads the standard input. The
standard input can also be referenced by a name consisting of a single hyphen.
For example:
.sp
  pcregrep some-pattern /file1 - /file3
.sp
By default, each line that matches the 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. However, there are options that can change how
\fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it possible to
search for patterns that span line boundaries.
.P
Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
BUFSIZ is defined in \fB<stdio.h>\fP.
.P
If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
\fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
The \fB--locale\fP option can be used to override this.
.
.SH OPTIONS
.rs
.TP 10
\fB--\fP
This terminate the list of options. It is useful if the next item on the
command line starts with a hyphen but is not an option. This allows for the
processing of patterns and filenames that start with hyphens.
.TP
\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
Output \fInumber\fP lines of context after each matching line. If filenames
and/or line numbers are being output, a hyphen separator is used instead of a
colon for the context lines. A line containing "--" is output between each
group of lines, unless they are in fact contiguous in the input file. The value
of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
guarantees to have up to 8K of following text available for context output.
.TP
\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
Output \fInumber\fP lines of context before each matching line. If filenames
and/or line numbers are being output, a hyphen separator is used instead of a
colon for the context lines. A line containing "--" is output between each
group of lines, unless they are in fact contiguous in the input file. The value
of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
guarantees to have up to 8K of preceding text available for context output.
.TP
\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
Output \fInumber\fP lines of context both before and after each matching line.
This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
.TP
\fB-c\fP, \fB--count\fP
Do not output individual lines; instead just output a count of the number of
lines that would otherwise have been output. If several files are given, a
count is output for each of them. In this mode, the \fB-A\fP, \fB-B\fP, and
\fB-C\fP options are ignored.
.TP
\fB--colour\fP, \fB--color\fP
If this option is given without any data, it is equivalent to "--colour=auto".
If data is required, it must be given in the same shell item, separated by an
equals sign.
.TP
\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
This option specifies under what circumstances the part of a line that matched
a pattern should be coloured in the output. The value may be "never" (the
default), "always", or "auto". In the latter case, colouring happens only if
the standard output is connected to a terminal. The colour can be specified by
setting the environment variable PCREGREP_COLOUR or PCREGREP_COLOR. The value
of this variable should be a string of two numbers, separated by a semicolon.
They are copied directly into the control string for setting colour on a
terminal, so it is your responsibility to ensure that they make sense. If
neither of the environment variables is set, the default is "1;31", which gives
red.
.TP
\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
If an input path is not a regular file or a directory, "action" specifies how
it is to be processed. Valid values are "read" (the default) or "skip"
(silently skip the path).
.TP
\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
If an input path is a directory, "action" specifies how it is to be processed.
Valid values are "read" (the default), "recurse" (equivalent to the \fB-r\fP
option), or "skip" (silently skip the path). In the default 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.
.TP
\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP,
\fB--regexp=\fP\fIpattern\fP Specify a pattern to be matched. This option can
be used multiple times in order to specify several patterns. It can also be
used as a way of specifying a single pattern that starts with a hyphen. When
\fB-e\fP is used, no argument pattern is taken from the command line; all
arguments are treated as file names. There is an overall maximum of 100
patterns. They are applied to each line in the order in which they are defined
until one matches (or fails to match if \fB-v\fP is used). If \fB-f\fP is used
with \fB-e\fP, the command line patterns are matched first, followed by the
patterns from the file, independent of the order in which these options are
specified. Note that multiple use of \fB-e\fP is not the same as a single
pattern with alternatives. For example, X|Y finds the first character in a line
that is X or Y, whereas if the two patterns are given separately,
\fBpcregrep\fP finds X if it is present, even if it follows Y in the line. It
finds Y only if there is no X in the line. This really matters only if you are
using \fB-o\fP to show the portion of the line that matched.
.TP
\fB--exclude\fP=\fIpattern\fP
When \fBpcregrep\fP is searching the files in a directory as a consequence of
the \fB-r\fP (recursive search) option, any files whose names match the pattern
are excluded. The pattern is a PCRE regular expression. If a file name matches
both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
form for this option.
.TP
\fB-F\fP, \fB--fixed-strings\fP
Interpret each pattern as a list of fixed strings, separated by newlines,
instead of as a regular expression. The \fB-w\fP (match as a word) and \fB-x\fP
(match whole line) options can be used with \fB-F\fP. They apply to each of the
fixed strings. A line is selected if any of the fixed strings are found in it
(subject to \fB-w\fP or \fB-x\fP, if present).
.TP
\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
Read a number of patterns from the file, one per line, and match them against
each line of input. A data line is output if any of the patterns match it. The
filename can be given as "-" to refer to the standard input. When \fB-f\fP is
used, patterns specified on the command line using \fB-e\fP may also be
present; they are tested before the file's patterns. However, no other pattern
is taken from the command line; all arguments are treated as file names. There
is an overall maximum of 100 patterns. Trailing white space is removed from
each line, and blank lines are ignored. An empty file contains no patterns and
therefore matches nothing.
.TP
\fB-H\fP, \fB--with-filename\fP
Force the inclusion of the filename at the start of output lines when searching
a single file. By default, the filename is not shown in this case. For matching
lines, the filename is followed by a colon and a space; for context lines, a
hyphen separator is used. If a line number is also being output, it follows the
file name without a space.
.TP
\fB-h\fP, \fB--no-filename\fP
Suppress the output filenames when searching multiple files. By default,
filenames are shown when multiple files are searched. For matching lines, the
filename is followed by a colon and a space; for context lines, a hyphen
separator is used. If a line number is also being output, it follows the file
name without a space.
.TP
\fB--help\fP
Output a brief help message and exit.
.TP
\fB-i\fP, \fB--ignore-case\fP
Ignore upper/lower case distinctions during comparisons.
.TP
\fB--include\fP=\fIpattern\fP
When \fBpcregrep\fP is searching the files in a directory as a consequence of
the \fB-r\fP (recursive search) option, only those files whose names match the
pattern are included. The pattern is a PCRE regular expression. If a file name
matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no
short form for this option.
.TP
\fB-L\fP, \fB--files-without-match\fP
Instead of outputting lines from the files, just output the names of the files
that do not contain any lines that would have been output. Each file name is
output once, on a separate line.
.TP
\fB-l\fP, \fB--files-with-matches\fP
Instead of outputting lines from the files, just output the names of the files
containing lines that would have been output. Each file name is output
once, on a separate line. Searching stops as soon as a matching line is found
in a file.
.TP
\fB--label\fP=\fIname\fP
This option supplies a name to be used for the standard input when file names
are being output. If not supplied, "(standard input)" is used. There is no
short form for this option.
.TP
\fB--locale\fP=\fIlocale-name\fP
This option specifies a locale to be used for pattern matching. It overrides
the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no
locale is specified, the PCRE library's default (usually the "C" locale) is
used. There is no short form for this option.
.TP
\fB-M\fP, \fB--multiline\fP
Allow patterns to match more than one line. When this option is given, patterns
may usefully contain literal newline characters and internal occurrences of ^
and $ characters. The output for any one match may consist of more than one
line. When this option is set, the PCRE library is called in "multiline" mode.
There is a limit to the number of lines that can be matched, imposed by the way
that \fBpcregrep\fP buffers the input file as it scans it. However,
\fBpcregrep\fP ensures that at least 8K characters or the rest of the document
(whichever is the shorter) are available for forward matching, and similarly
the previous 8K characters (or all the previous characters, if fewer than 8K)
are guaranteed to be available for lookbehind assertions.
.TP
\fB-n\fP, \fB--line-number\fP
Precede each output line by its line number in the file, followed by a colon
and a space for matching lines or a hyphen and a space for context lines. If
the filename is also being output, it precedes the line number.
.TP
\fB-o\fP, \fB--only-matching\fP
Show only the part of the line that matched a pattern. In this mode, no
context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are
ignored.
.TP
\fB-q\fP, \fB--quiet\fP
Work quietly, that is, display nothing except error messages. The exit
status indicates whether or not any matches were found.
.TP
\fB-r\fP, \fB--recursive\fP
If any given path is a directory, recursively scan the files it contains,
taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a
directory is read as a normal file; in some operating systems this gives an
immediate end-of-file. This option is a shorthand for setting the \fB-d\fP
option to "recurse".
.TP
\fB-s\fP, \fB--no-messages\fP
Suppress error messages about non-existent or unreadable files. Such files are
quietly skipped. However, the return code is still 2, even if matches were
found in other files.
.TP
\fB-u\fP, \fB--utf-8\fP
Operate in UTF-8 mode. This option is available only if PCRE has been compiled
with UTF-8 support. Both patterns and subject lines must be valid strings of
UTF-8 characters.
.TP
\fB-V\fP, \fB--version\fP
Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
used to the standard error stream.
.TP
\fB-v\fP, \fB--invert-match\fP
Invert the sense of the match, so that lines which do \fInot\fP match any of
the patterns are the ones that are found.
.TP
\fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP
Force the patterns to match only whole words. This is equivalent to having \eb
at the start and end of the pattern.
.TP
\fB-x\fP, \fB--line-regex\fP, \fP--line-regexp\fP
Force the patterns to be anchored (each must start matching at the beginning of
a line) and in addition, require them to match entire lines. This is
equivalent to having ^ and $ characters at the start and end of each
alternative branch in every pattern.
.
.
.SH "ENVIRONMENT VARIABLES"
.rs
.sp
The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that
order, for a locale. The first one that is set is used. This can be overridden
by the \fB--locale\fP option. If no locale is set, the PCRE library's default
(usually the "C" locale) is used.
.
.
.SH "OPTIONS COMPATIBILITY"
.rs
.sp
The majority of short and long forms of \fBpcregrep\fP's options are the same
as in the GNU \fBgrep\fP program. Any long option of the form
\fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP
(PCRE terminology). However, the \fB--locale\fP, \fB-M\fP, \fB--multiline\fP,
\fB-u\fP, and \fB--utf-8\fP options are specific to \fBpcregrep\fP.
.
.
.SH "OPTIONS WITH DATA"
.rs
.sp
There are four different ways in which an option with data can be specified.
If a short form option is used, the data may follow immediately, or in the next
command line item. For example:
.sp
  -f/some/file
  -f /some/file
.sp
If a long form option is used, the data may appear in the same command line
item, separated by an equals character, or (with one exception) it may appear
in the next command line item. For example:
.sp
  --file=/some/file
  --file /some/file
.sp
Note, however, that if you want to supply a file name beginning with ~ as data
in a shell command, and have the shell expand ~ to a home directory, you must
separate the file name from the option, because the shell does not treat ~
specially unless it is at the start of an item.
.P
The exception to the above is the \fB--colour\fP (or \fB--color\fP) option,
for which the data is optional. If this option does have data, it must be given
in the first form, using an equals character. Otherwise it will be assumed that
it has no data.
.
.
.SH MATCHING ERRORS
.rs
.sp
It is possible to supply a regular expression that takes a very long time to
fail to match certain lines. Such patterns normally involve nested indefinite
repeats, for example: (a+)*\ed when matched against a line of a's with no final
digit. The PCRE matching function has a resource limit that causes it to abort
in these circumstances. If this happens, \fBpcregrep\fP outputs an error
message and the line that caused the problem to the standard error stream. If
there are more than 20 such errors, \fBpcregrep\fP gives up.
.
.
.SH DIAGNOSTICS
.rs
.sp
Exit status is 0 if any matches were found, 1 if no matches were found, and 2
for syntax errors and non-existent or inacessible files (even if matches were
found in other files) or too many matching errors. Using the \fB-s\fP option to
suppress error messages about inaccessble files does not affect the return
code.
.
.
.SH AUTHOR
.rs
.sp
Philip Hazel
.br
University Computing Service
.br
Cambridge CB2 3QG, England.
.P
.in 0
Last updated: 23 January 2006
.br
Copyright (c) 1997-2006 University of Cambridge.
1	nigel	49	.TH PCREGREP 1
2			.SH NAME
3			pcregrep - a grep with Perl-compatible regular expressions.
4			.SH SYNOPSIS
5	nigel	87	.B pcregrep [options] [long options] [pattern] [path1 path2 ...]
6	nigel	75	.
7	nigel	49	.SH DESCRIPTION
8	nigel	63	.rs
9			.sp
10	nigel	75	\fBpcregrep\fP searches files for character patterns, in the same way as other
11	nigel	49	grep commands do, but it uses the PCRE regular expression library to support
12			patterns that are compatible with the regular expressions of Perl 5. See
13	nigel	63	.\" HREF
14	nigel	75	\fBpcrepattern\fP
15	nigel	63	.\"
16			for a full description of syntax and semantics of the regular expressions that
17			PCRE supports.
18	nigel	75	.P
19	nigel	87	Patterns, whether supplied on the command line or in a separate file, are given
20			without delimiters. For example:
21			.sp
22			pcregrep Thursday /etc/motd
23			.sp
24			If you attempt to use delimiters (for example, by surrounding a pattern with
25			slashes, as is common in Perl scripts), they are interpreted as part of the
26			pattern. Quotes can of course be used on the command line because they are
27			interpreted by the shell, and indeed they are required if a pattern contains
28			white space or shell metacharacters.
29	nigel	75	.P
30	nigel	87	The first argument that follows any option settings is treated as the single
31			pattern to be matched when neither \fB-e\fP nor \fB-f\fP is present.
32			Conversely, when one or both of these options are used to specify patterns, all
33			arguments are treated as path names. At least one of \fB-e\fP, \fB-f\fP, or an
34			argument pattern must be provided.
35			.P
36	nigel	77	If no files are specified, \fBpcregrep\fP reads the standard input. The
37			standard input can also be referenced by a name consisting of a single hyphen.
38			For example:
39			.sp
40			pcregrep some-pattern /file1 - /file3
41			.sp
42			By default, each line that matches the pattern is copied to the standard
43	nigel	87	output, and if there is more than one file, the file name is output at the
44			start of each line. However, there are options that can change how
45	nigel	77	\fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it possible to
46			search for patterns that span line boundaries.
47	nigel	75	.P
48	nigel	77	Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
49			BUFSIZ is defined in \fB<stdio.h>\fP.
50	nigel	87	.P
51			If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
52			\fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
53			The \fB--locale\fP option can be used to override this.
54	nigel	75	.
55	nigel	49	.SH OPTIONS
56	nigel	63	.rs
57	nigel	49	.TP 10
58	nigel	77	\fB--\fP
59			This terminate the list of options. It is useful if the next item on the
60	nigel	87	command line starts with a hyphen but is not an option. This allows for the
61			processing of patterns and filenames that start with hyphens.
62	nigel	49	.TP
63	nigel	87	\fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
64			Output \fInumber\fP lines of context after each matching line. If filenames
65			and/or line numbers are being output, a hyphen separator is used instead of a
66			colon for the context lines. A line containing "--" is output between each
67	nigel	77	group of lines, unless they are in fact contiguous in the input file. The value
68			of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
69	nigel	87	guarantees to have up to 8K of following text available for context output.
70	nigel	77	.TP
71	nigel	87	\fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
72			Output \fInumber\fP lines of context before each matching line. If filenames
73			and/or line numbers are being output, a hyphen separator is used instead of a
74			colon for the context lines. A line containing "--" is output between each
75	nigel	77	group of lines, unless they are in fact contiguous in the input file. The value
76			of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
77	nigel	87	guarantees to have up to 8K of preceding text available for context output.
78	nigel	77	.TP
79	nigel	87	\fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
80			Output \fInumber\fP lines of context both before and after each matching line.
81	nigel	77	This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
82			.TP
83	nigel	87	\fB-c\fP, \fB--count\fP
84			Do not output individual lines; instead just output a count of the number of
85			lines that would otherwise have been output. If several files are given, a
86			count is output for each of them. In this mode, the \fB-A\fP, \fB-B\fP, and
87			\fB-C\fP options are ignored.
88	nigel	49	.TP
89	nigel	87	\fB--colour\fP, \fB--color\fP
90			If this option is given without any data, it is equivalent to "--colour=auto".
91			If data is required, it must be given in the same shell item, separated by an
92			equals sign.
93			.TP
94			\fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
95			This option specifies under what circumstances the part of a line that matched
96			a pattern should be coloured in the output. The value may be "never" (the
97			default), "always", or "auto". In the latter case, colouring happens only if
98			the standard output is connected to a terminal. The colour can be specified by
99			setting the environment variable PCREGREP_COLOUR or PCREGREP_COLOR. The value
100			of this variable should be a string of two numbers, separated by a semicolon.
101			They are copied directly into the control string for setting colour on a
102			terminal, so it is your responsibility to ensure that they make sense. If
103			neither of the environment variables is set, the default is "1;31", which gives
104			red.
105			.TP
106			\fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
107			If an input path is not a regular file or a directory, "action" specifies how
108			it is to be processed. Valid values are "read" (the default) or "skip"
109			(silently skip the path).
110			.TP
111			\fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
112			If an input path is a directory, "action" specifies how it is to be processed.
113			Valid values are "read" (the default), "recurse" (equivalent to the \fB-r\fP
114			option), or "skip" (silently skip the path). In the default case, directories
115			are read as if they were ordinary files. In some operating systems the effect
116			of reading a directory like this is an immediate end-of-file.
117			.TP
118			\fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP,
119			\fB--regexp=\fP\fIpattern\fP Specify a pattern to be matched. This option can
120			be used multiple times in order to specify several patterns. It can also be
121			used as a way of specifying a single pattern that starts with a hyphen. When
122			\fB-e\fP is used, no argument pattern is taken from the command line; all
123			arguments are treated as file names. There is an overall maximum of 100
124			patterns. They are applied to each line in the order in which they are defined
125			until one matches (or fails to match if \fB-v\fP is used). If \fB-f\fP is used
126			with \fB-e\fP, the command line patterns are matched first, followed by the
127			patterns from the file, independent of the order in which these options are
128			specified. Note that multiple use of \fB-e\fP is not the same as a single
129			pattern with alternatives. For example, X\|Y finds the first character in a line
130			that is X or Y, whereas if the two patterns are given separately,
131			\fBpcregrep\fP finds X if it is present, even if it follows Y in the line. It
132			finds Y only if there is no X in the line. This really matters only if you are
133			using \fB-o\fP to show the portion of the line that matched.
134			.TP
135	nigel	77	\fB--exclude\fP=\fIpattern\fP
136			When \fBpcregrep\fP is searching the files in a directory as a consequence of
137			the \fB-r\fP (recursive search) option, any files whose names match the pattern
138			are excluded. The pattern is a PCRE regular expression. If a file name matches
139			both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
140			form for this option.
141			.TP
142	nigel	87	\fB-F\fP, \fB--fixed-strings\fP
143			Interpret each pattern as a list of fixed strings, separated by newlines,
144			instead of as a regular expression. The \fB-w\fP (match as a word) and \fB-x\fP
145			(match whole line) options can be used with \fB-F\fP. They apply to each of the
146			fixed strings. A line is selected if any of the fixed strings are found in it
147			(subject to \fB-w\fP or \fB-x\fP, if present).
148	nigel	53	.TP
149	nigel	87	\fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
150			Read a number of patterns from the file, one per line, and match them against
151			each line of input. A data line is output if any of the patterns match it. The
152			filename can be given as "-" to refer to the standard input. When \fB-f\fP is
153			used, patterns specified on the command line using \fB-e\fP may also be
154			present; they are tested before the file's patterns. However, no other pattern
155			is taken from the command line; all arguments are treated as file names. There
156			is an overall maximum of 100 patterns. Trailing white space is removed from
157			each line, and blank lines are ignored. An empty file contains no patterns and
158			therefore matches nothing.
159	nigel	49	.TP
160	nigel	87	\fB-H\fP, \fB--with-filename\fP
161			Force the inclusion of the filename at the start of output lines when searching
162			a single file. By default, the filename is not shown in this case. For matching
163			lines, the filename is followed by a colon and a space; for context lines, a
164			hyphen separator is used. If a line number is also being output, it follows the
165			file name without a space.
166			.TP
167			\fB-h\fP, \fB--no-filename\fP
168			Suppress the output filenames when searching multiple files. By default,
169			filenames are shown when multiple files are searched. For matching lines, the
170			filename is followed by a colon and a space; for context lines, a hyphen
171			separator is used. If a line number is also being output, it follows the file
172			name without a space.
173			.TP
174			\fB--help\fP
175			Output a brief help message and exit.
176			.TP
177			\fB-i\fP, \fB--ignore-case\fP
178	nigel	49	Ignore upper/lower case distinctions during comparisons.
179			.TP
180	nigel	77	\fB--include\fP=\fIpattern\fP
181			When \fBpcregrep\fP is searching the files in a directory as a consequence of
182	nigel	87	the \fB-r\fP (recursive search) option, only those files whose names match the
183	nigel	77	pattern are included. The pattern is a PCRE regular expression. If a file name
184			matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no
185			short form for this option.
186			.TP
187	nigel	87	\fB-L\fP, \fB--files-without-match\fP
188			Instead of outputting lines from the files, just output the names of the files
189			that do not contain any lines that would have been output. Each file name is
190			output once, on a separate line.
191	nigel	77	.TP
192	nigel	87	\fB-l\fP, \fB--files-with-matches\fP
193			Instead of outputting lines from the files, just output the names of the files
194			containing lines that would have been output. Each file name is output
195			once, on a separate line. Searching stops as soon as a matching line is found
196			in a file.
197	nigel	49	.TP
198	nigel	77	\fB--label\fP=\fIname\fP
199			This option supplies a name to be used for the standard input when file names
200	nigel	87	are being output. If not supplied, "(standard input)" is used. There is no
201	nigel	77	short form for this option.
202			.TP
203	nigel	87	\fB--locale\fP=\fIlocale-name\fP
204			This option specifies a locale to be used for pattern matching. It overrides
205			the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no
206			locale is specified, the PCRE library's default (usually the "C" locale) is
207			used. There is no short form for this option.
208			.TP
209			\fB-M\fP, \fB--multiline\fP
210	nigel	77	Allow patterns to match more than one line. When this option is given, patterns
211			may usefully contain literal newline characters and internal occurrences of ^
212			and $ characters. The output for any one match may consist of more than one
213			line. When this option is set, the PCRE library is called in "multiline" mode.
214			There is a limit to the number of lines that can be matched, imposed by the way
215			that \fBpcregrep\fP buffers the input file as it scans it. However,
216			\fBpcregrep\fP ensures that at least 8K characters or the rest of the document
217			(whichever is the shorter) are available for forward matching, and similarly
218			the previous 8K characters (or all the previous characters, if fewer than 8K)
219			are guaranteed to be available for lookbehind assertions.
220			.TP
221	nigel	87	\fB-n\fP, \fB--line-number\fP
222			Precede each output line by its line number in the file, followed by a colon
223			and a space for matching lines or a hyphen and a space for context lines. If
224			the filename is also being output, it precedes the line number.
225	nigel	49	.TP
226	nigel	87	\fB-o\fP, \fB--only-matching\fP
227			Show only the part of the line that matched a pattern. In this mode, no
228			context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are
229			ignored.
230	nigel	77	.TP
231	nigel	87	\fB-q\fP, \fB--quiet\fP
232			Work quietly, that is, display nothing except error messages. The exit
233			status indicates whether or not any matches were found.
234			.TP
235			\fB-r\fP, \fB--recursive\fP
236	nigel	77	If any given path is a directory, recursively scan the files it contains,
237	nigel	87	taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a
238			directory is read as a normal file; in some operating systems this gives an
239			immediate end-of-file. This option is a shorthand for setting the \fB-d\fP
240			option to "recurse".
241	nigel	53	.TP
242	nigel	87	\fB-s\fP, \fB--no-messages\fP
243	nigel	77	Suppress error messages about non-existent or unreadable files. Such files are
244			quietly skipped. However, the return code is still 2, even if matches were
245			found in other files.
246	nigel	49	.TP
247	nigel	87	\fB-u\fP, \fB--utf-8\fP
248	nigel	63	Operate in UTF-8 mode. This option is available only if PCRE has been compiled
249	nigel	87	with UTF-8 support. Both patterns and subject lines must be valid strings of
250			UTF-8 characters.
251	nigel	63	.TP
252	nigel	87	\fB-V\fP, \fB--version\fP
253	nigel	77	Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
254			used to the standard error stream.
255			.TP
256	nigel	87	\fB-v\fP, \fB--invert-match\fP
257			Invert the sense of the match, so that lines which do \fInot\fP match any of
258			the patterns are the ones that are found.
259	nigel	49	.TP
260	nigel	87	\fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP
261			Force the patterns to match only whole words. This is equivalent to having \eb
262	nigel	77	at the start and end of the pattern.
263			.TP
264	nigel	87	\fB-x\fP, \fB--line-regex\fP, \fP--line-regexp\fP
265			Force the patterns to be anchored (each must start matching at the beginning of
266			a line) and in addition, require them to match entire lines. This is
267	nigel	49	equivalent to having ^ and $ characters at the start and end of each
268	nigel	87	alternative branch in every pattern.
269	nigel	75	.
270	nigel	87	.
271			.SH "ENVIRONMENT VARIABLES"
272	nigel	63	.rs
273			.sp
274	nigel	87	The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that
275			order, for a locale. The first one that is set is used. This can be overridden
276			by the \fB--locale\fP option. If no locale is set, the PCRE library's default
277			(usually the "C" locale) is used.
278			.
279			.
280			.SH "OPTIONS COMPATIBILITY"
281			.rs
282	nigel	75	.sp
283	nigel	87	The majority of short and long forms of \fBpcregrep\fP's options are the same
284			as in the GNU \fBgrep\fP program. Any long option of the form
285			\fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP
286			(PCRE terminology). However, the \fB--locale\fP, \fB-M\fP, \fB--multiline\fP,
287			\fB-u\fP, and \fB--utf-8\fP options are specific to \fBpcregrep\fP.
288	nigel	77	.
289	nigel	87	.
290	nigel	77	.SH "OPTIONS WITH DATA"
291			.rs
292	nigel	75	.sp
293	nigel	77	There are four different ways in which an option with data can be specified.
294			If a short form option is used, the data may follow immediately, or in the next
295			command line item. For example:
296			.sp
297			-f/some/file
298			-f /some/file
299			.sp
300			If a long form option is used, the data may appear in the same command line
301	nigel	87	item, separated by an equals character, or (with one exception) it may appear
302			in the next command line item. For example:
303	nigel	77	.sp
304			--file=/some/file
305			--file /some/file
306			.sp
307	nigel	87	Note, however, that if you want to supply a file name beginning with ~ as data
308			in a shell command, and have the shell expand ~ to a home directory, you must
309			separate the file name from the option, because the shell does not treat ~
310			specially unless it is at the start of an item.
311			.P
312			The exception to the above is the \fB--colour\fP (or \fB--color\fP) option,
313			for which the data is optional. If this option does have data, it must be given
314			in the first form, using an equals character. Otherwise it will be assumed that
315			it has no data.
316	nigel	75	.
317	nigel	87	.
318			.SH MATCHING ERRORS
319			.rs
320			.sp
321			It is possible to supply a regular expression that takes a very long time to
322			fail to match certain lines. Such patterns normally involve nested indefinite
323			repeats, for example: (a+)*\ed when matched against a line of a's with no final
324			digit. The PCRE matching function has a resource limit that causes it to abort
325			in these circumstances. If this happens, \fBpcregrep\fP outputs an error
326			message and the line that caused the problem to the standard error stream. If
327			there are more than 20 such errors, \fBpcregrep\fP gives up.
328			.
329			.
330	nigel	49	.SH DIAGNOSTICS
331	nigel	63	.rs
332			.sp
333	nigel	49	Exit status is 0 if any matches were found, 1 if no matches were found, and 2
334	nigel	77	for syntax errors and non-existent or inacessible files (even if matches were
335	nigel	87	found in other files) or too many matching errors. Using the \fB-s\fP option to
336			suppress error messages about inaccessble files does not affect the return
337			code.
338	nigel	75	.
339			.
340	nigel	49	.SH AUTHOR
341	nigel	63	.rs
342			.sp
343	nigel	77	Philip Hazel
344	nigel	63	.br
345			University Computing Service
346			.br
347			Cambridge CB2 3QG, England.
348	nigel	75	.P
349	nigel	63	.in 0
350	nigel	87	Last updated: 23 January 2006
351	nigel	49	.br
352	nigel	87	Copyright (c) 1997-2006 University of Cambridge.