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Add .gz and .bz2 optional support to pcregrep.

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 93 \fBpcrepattern\fP(3)
15 nigel 63 .\"
16 nigel 93 for a full description of syntax and semantics of the regular expressions
17     that 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 ph10 279 pattern. Quotes can of course be used to delimit patterns on the command line
27     because they are interpreted by the shell, and indeed they are required if a
28     pattern contains 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 ph10 281 By default, each line that matches a 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 ph10 279 start of each line, followed by a colon. However, there are options that can
45     change how \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it
46     possible to search for patterns that span line boundaries. What defines a line
47     boundary is controlled by the \fB-N\fP (\fB--newline\fP) option.
48 nigel 75 .P
49 nigel 77 Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
50 ph10 286 BUFSIZ is defined in \fB<stdio.h>\fP. When there is more than one pattern
51     (specified by the use of \fB-e\fP and/or \fB-f\fP), each pattern is applied to
52     each line in the order in which they are defined, except that all the \fB-e\fP
53     patterns are tried before the \fB-f\fP patterns. As soon as one pattern matches
54 ph10 281 (or fails to match when \fB-v\fP is used), no further patterns are considered.
55 nigel 87 .P
56 ph10 281 When \fB--only-matching\fP, \fB--file-offsets\fP, or \fB--line-offsets\fP
57     is used, the output is the part of the line that matched (either shown
58     literally, or as an offset). In this case, scanning resumes immediately
59     following the match, so that further matches on the same line can be found.
60 ph10 286 If there are multiple patterns, they are all tried on the remainder of the
61     line. However, patterns that follow the one that matched are not tried on the
62 ph10 281 earlier part of the line.
63     .P
64 nigel 87 If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
65     \fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
66     The \fB--locale\fP option can be used to override this.
67 nigel 75 .
68 ph10 286 .SH "SUPPORT FOR COMPRESSED FILES"
69     .rs
70     .sp
71     It is possible to compile \fBpcregrep\fP so that it uses \fBlibz\fP or
72     \fBlibbz2\fP to read files whose names end in \fB.gz\fP or \fB.bz2\fP,
73     respectively. You can find out whether your binary has support for one or both
74     of these file types by running it with the \fB--help\fP option. If the
75     appropriate support is not present, files are treated as plain text. The
76     standard input is always so treated.
77     .
78 nigel 49 .SH OPTIONS
79 nigel 63 .rs
80 nigel 49 .TP 10
81 nigel 77 \fB--\fP
82     This terminate the list of options. It is useful if the next item on the
83 nigel 87 command line starts with a hyphen but is not an option. This allows for the
84     processing of patterns and filenames that start with hyphens.
85 nigel 49 .TP
86 nigel 87 \fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
87     Output \fInumber\fP lines of context after each matching line. If filenames
88     and/or line numbers are being output, a hyphen separator is used instead of a
89     colon for the context lines. A line containing "--" is output between each
90 nigel 77 group of lines, unless they are in fact contiguous in the input file. The value
91     of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
92 nigel 87 guarantees to have up to 8K of following text available for context output.
93 nigel 77 .TP
94 nigel 87 \fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
95     Output \fInumber\fP lines of context before each matching line. If filenames
96     and/or line numbers are being output, a hyphen separator is used instead of a
97     colon for the context lines. A line containing "--" is output between each
98 nigel 77 group of lines, unless they are in fact contiguous in the input file. The value
99     of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
100 nigel 87 guarantees to have up to 8K of preceding text available for context output.
101 nigel 77 .TP
102 nigel 87 \fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
103     Output \fInumber\fP lines of context both before and after each matching line.
104 nigel 77 This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
105     .TP
106 nigel 87 \fB-c\fP, \fB--count\fP
107     Do not output individual lines; instead just output a count of the number of
108     lines that would otherwise have been output. If several files are given, a
109     count is output for each of them. In this mode, the \fB-A\fP, \fB-B\fP, and
110     \fB-C\fP options are ignored.
111 nigel 49 .TP
112 nigel 87 \fB--colour\fP, \fB--color\fP
113     If this option is given without any data, it is equivalent to "--colour=auto".
114     If data is required, it must be given in the same shell item, separated by an
115     equals sign.
116     .TP
117     \fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
118     This option specifies under what circumstances the part of a line that matched
119     a pattern should be coloured in the output. The value may be "never" (the
120     default), "always", or "auto". In the latter case, colouring happens only if
121     the standard output is connected to a terminal. The colour can be specified by
122     setting the environment variable PCREGREP_COLOUR or PCREGREP_COLOR. The value
123     of this variable should be a string of two numbers, separated by a semicolon.
124     They are copied directly into the control string for setting colour on a
125     terminal, so it is your responsibility to ensure that they make sense. If
126     neither of the environment variables is set, the default is "1;31", which gives
127     red.
128     .TP
129     \fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
130     If an input path is not a regular file or a directory, "action" specifies how
131     it is to be processed. Valid values are "read" (the default) or "skip"
132     (silently skip the path).
133     .TP
134     \fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
135     If an input path is a directory, "action" specifies how it is to be processed.
136     Valid values are "read" (the default), "recurse" (equivalent to the \fB-r\fP
137     option), or "skip" (silently skip the path). In the default case, directories
138     are read as if they were ordinary files. In some operating systems the effect
139     of reading a directory like this is an immediate end-of-file.
140     .TP
141 ph10 286 \fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP, \fB--regexp=\fP\fIpattern\fP
142 ph10 279 Specify a pattern to be matched. This option can be used multiple times in
143     order to specify several patterns. It can also be used as a way of specifying a
144     single pattern that starts with a hyphen. When \fB-e\fP is used, no argument
145     pattern is taken from the command line; all arguments are treated as file
146     names. There is an overall maximum of 100 patterns. They are applied to each
147     line in the order in which they are defined until one matches (or fails to
148     match if \fB-v\fP is used). If \fB-f\fP is used with \fB-e\fP, the command line
149     patterns are matched first, followed by the patterns from the file, independent
150     of the order in which these options are specified. Note that multiple use of
151     \fB-e\fP is not the same as a single pattern with alternatives. For example,
152     X|Y finds the first character in a line that is X or Y, whereas if the two
153     patterns are given separately, \fBpcregrep\fP finds X if it is present, even if
154     it follows Y in the line. It finds Y only if there is no X in the line. This
155     really matters only if you are using \fB-o\fP to show the part(s) of the line
156     that matched.
157 nigel 87 .TP
158 nigel 77 \fB--exclude\fP=\fIpattern\fP
159     When \fBpcregrep\fP is searching the files in a directory as a consequence of
160     the \fB-r\fP (recursive search) option, any files whose names match the pattern
161     are excluded. The pattern is a PCRE regular expression. If a file name matches
162     both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
163     form for this option.
164     .TP
165 nigel 87 \fB-F\fP, \fB--fixed-strings\fP
166     Interpret each pattern as a list of fixed strings, separated by newlines,
167     instead of as a regular expression. The \fB-w\fP (match as a word) and \fB-x\fP
168     (match whole line) options can be used with \fB-F\fP. They apply to each of the
169     fixed strings. A line is selected if any of the fixed strings are found in it
170     (subject to \fB-w\fP or \fB-x\fP, if present).
171 nigel 53 .TP
172 nigel 87 \fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
173     Read a number of patterns from the file, one per line, and match them against
174     each line of input. A data line is output if any of the patterns match it. The
175     filename can be given as "-" to refer to the standard input. When \fB-f\fP is
176     used, patterns specified on the command line using \fB-e\fP may also be
177     present; they are tested before the file's patterns. However, no other pattern
178     is taken from the command line; all arguments are treated as file names. There
179     is an overall maximum of 100 patterns. Trailing white space is removed from
180     each line, and blank lines are ignored. An empty file contains no patterns and
181 ph10 286 therefore matches nothing. See also the comments about multiple patterns versus
182 ph10 281 a single pattern with alternatives in the description of \fB-e\fP above.
183 nigel 49 .TP
184 ph10 280 \fB--file-offsets\fP
185     Instead of showing lines or parts of lines that match, show each match as an
186     offset from the start of the file and a length, separated by a comma. In this
187     mode, no context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP
188     options are ignored. If there is more than one match in a line, each of them is
189     shown separately. This option is mutually exclusive with \fB--line-offsets\fP
190     and \fB--only-matching\fP.
191     .TP
192 nigel 87 \fB-H\fP, \fB--with-filename\fP
193     Force the inclusion of the filename at the start of output lines when searching
194     a single file. By default, the filename is not shown in this case. For matching
195     lines, the filename is followed by a colon and a space; for context lines, a
196     hyphen separator is used. If a line number is also being output, it follows the
197     file name without a space.
198     .TP
199     \fB-h\fP, \fB--no-filename\fP
200     Suppress the output filenames when searching multiple files. By default,
201     filenames are shown when multiple files are searched. For matching lines, the
202     filename is followed by a colon and a space; for context lines, a hyphen
203     separator is used. If a line number is also being output, it follows the file
204     name without a space.
205     .TP
206     \fB--help\fP
207 ph10 286 Output a help message, giving brief details of the command options and file
208     type support, and then exit.
209 nigel 87 .TP
210     \fB-i\fP, \fB--ignore-case\fP
211 nigel 49 Ignore upper/lower case distinctions during comparisons.
212     .TP
213 nigel 77 \fB--include\fP=\fIpattern\fP
214     When \fBpcregrep\fP is searching the files in a directory as a consequence of
215 nigel 87 the \fB-r\fP (recursive search) option, only those files whose names match the
216 nigel 77 pattern are included. The pattern is a PCRE regular expression. If a file name
217     matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no
218     short form for this option.
219     .TP
220 nigel 87 \fB-L\fP, \fB--files-without-match\fP
221     Instead of outputting lines from the files, just output the names of the files
222     that do not contain any lines that would have been output. Each file name is
223     output once, on a separate line.
224 nigel 77 .TP
225 nigel 87 \fB-l\fP, \fB--files-with-matches\fP
226     Instead of outputting lines from the files, just output the names of the files
227     containing lines that would have been output. Each file name is output
228     once, on a separate line. Searching stops as soon as a matching line is found
229     in a file.
230 nigel 49 .TP
231 nigel 77 \fB--label\fP=\fIname\fP
232     This option supplies a name to be used for the standard input when file names
233 nigel 87 are being output. If not supplied, "(standard input)" is used. There is no
234 nigel 77 short form for this option.
235     .TP
236 ph10 280 \fB--line-offsets\fP
237 ph10 286 Instead of showing lines or parts of lines that match, show each match as a
238     line number, the offset from the start of the line, and a length. The line
239     number is terminated by a colon (as usual; see the \fB-n\fP option), and the
240 ph10 280 offset and length are separated by a comma. In this mode, no context is shown.
241     That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are ignored. If there is
242     more than one match in a line, each of them is shown separately. This option is
243     mutually exclusive with \fB--file-offsets\fP and \fB--only-matching\fP.
244     .TP
245 nigel 87 \fB--locale\fP=\fIlocale-name\fP
246     This option specifies a locale to be used for pattern matching. It overrides
247     the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no
248     locale is specified, the PCRE library's default (usually the "C" locale) is
249     used. There is no short form for this option.
250     .TP
251     \fB-M\fP, \fB--multiline\fP
252 nigel 77 Allow patterns to match more than one line. When this option is given, patterns
253     may usefully contain literal newline characters and internal occurrences of ^
254     and $ characters. The output for any one match may consist of more than one
255     line. When this option is set, the PCRE library is called in "multiline" mode.
256     There is a limit to the number of lines that can be matched, imposed by the way
257     that \fBpcregrep\fP buffers the input file as it scans it. However,
258     \fBpcregrep\fP ensures that at least 8K characters or the rest of the document
259     (whichever is the shorter) are available for forward matching, and similarly
260     the previous 8K characters (or all the previous characters, if fewer than 8K)
261     are guaranteed to be available for lookbehind assertions.
262     .TP
263 nigel 91 \fB-N\fP \fInewline-type\fP, \fB--newline=\fP\fInewline-type\fP
264 ph10 149 The PCRE library supports five different conventions for indicating
265 nigel 91 the ends of lines. They are the single-character sequences CR (carriage return)
266 ph10 150 and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention,
267 ph10 149 which recognizes any of the preceding three types, and an "any" convention, in
268 nigel 93 which any Unicode line ending sequence is assumed to end a line. The Unicode
269     sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF
270     (formfeed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and
271 ph10 149 PS (paragraph separator, U+2029).
272 nigel 93 .sp
273     When the PCRE library is built, a default line-ending sequence is specified.
274     This is normally the standard sequence for the operating system. Unless
275     otherwise specified by this option, \fBpcregrep\fP uses the library's default.
276 ph10 149 The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
277     makes it possible to use \fBpcregrep\fP on files that have come from other
278     environments without having to modify their line endings. If the data that is
279     being scanned does not agree with the convention set by this option,
280     \fBpcregrep\fP may behave in strange ways.
281 nigel 91 .TP
282 nigel 87 \fB-n\fP, \fB--line-number\fP
283     Precede each output line by its line number in the file, followed by a colon
284     and a space for matching lines or a hyphen and a space for context lines. If
285 ph10 286 the filename is also being output, it precedes the line number. This option is
286 ph10 280 forced if \fB--line-offsets\fP is used.
287 nigel 49 .TP
288 nigel 87 \fB-o\fP, \fB--only-matching\fP
289     Show only the part of the line that matched a pattern. In this mode, no
290     context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are
291 ph10 286 ignored. If there is more than one match in a line, each of them is shown
292     separately. If \fB-o\fP is combined with \fB-v\fP (invert the sense of the
293     match to find non-matching lines), no output is generated, but the return code
294     is set appropriately. This option is mutually exclusive with
295 ph10 280 \fB--file-offsets\fP and \fB--line-offsets\fP.
296 nigel 77 .TP
297 nigel 87 \fB-q\fP, \fB--quiet\fP
298     Work quietly, that is, display nothing except error messages. The exit
299     status indicates whether or not any matches were found.
300     .TP
301     \fB-r\fP, \fB--recursive\fP
302 nigel 77 If any given path is a directory, recursively scan the files it contains,
303 nigel 87 taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a
304     directory is read as a normal file; in some operating systems this gives an
305     immediate end-of-file. This option is a shorthand for setting the \fB-d\fP
306     option to "recurse".
307 nigel 53 .TP
308 nigel 87 \fB-s\fP, \fB--no-messages\fP
309 nigel 77 Suppress error messages about non-existent or unreadable files. Such files are
310     quietly skipped. However, the return code is still 2, even if matches were
311     found in other files.
312 nigel 49 .TP
313 nigel 87 \fB-u\fP, \fB--utf-8\fP
314 nigel 63 Operate in UTF-8 mode. This option is available only if PCRE has been compiled
315 nigel 87 with UTF-8 support. Both patterns and subject lines must be valid strings of
316     UTF-8 characters.
317 nigel 63 .TP
318 nigel 87 \fB-V\fP, \fB--version\fP
319 nigel 77 Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
320     used to the standard error stream.
321     .TP
322 nigel 87 \fB-v\fP, \fB--invert-match\fP
323     Invert the sense of the match, so that lines which do \fInot\fP match any of
324     the patterns are the ones that are found.
325 nigel 49 .TP
326 nigel 87 \fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP
327     Force the patterns to match only whole words. This is equivalent to having \eb
328 nigel 77 at the start and end of the pattern.
329     .TP
330 ph10 148 \fB-x\fP, \fB--line-regex\fP, \fB--line-regexp\fP
331 nigel 87 Force the patterns to be anchored (each must start matching at the beginning of
332     a line) and in addition, require them to match entire lines. This is
333 nigel 49 equivalent to having ^ and $ characters at the start and end of each
334 nigel 87 alternative branch in every pattern.
335 nigel 75 .
336 nigel 87 .
337     .SH "ENVIRONMENT VARIABLES"
338 nigel 63 .rs
339     .sp
340 nigel 87 The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that
341     order, for a locale. The first one that is set is used. This can be overridden
342     by the \fB--locale\fP option. If no locale is set, the PCRE library's default
343     (usually the "C" locale) is used.
344     .
345     .
346 nigel 91 .SH "NEWLINES"
347     .rs
348     .sp
349     The \fB-N\fP (\fB--newline\fP) option allows \fBpcregrep\fP to scan files with
350     different newline conventions from the default. However, the setting of this
351     option does not affect the way in which \fBpcregrep\fP writes information to
352     the standard error and output streams. It uses the string "\en" in C
353     \fBprintf()\fP calls to indicate newlines, relying on the C I/O library to
354     convert this to an appropriate sequence if the output is sent to a file.
355     .
356     .
357 nigel 87 .SH "OPTIONS COMPATIBILITY"
358     .rs
359 nigel 75 .sp
360 nigel 87 The majority of short and long forms of \fBpcregrep\fP's options are the same
361     as in the GNU \fBgrep\fP program. Any long option of the form
362     \fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP
363     (PCRE terminology). However, the \fB--locale\fP, \fB-M\fP, \fB--multiline\fP,
364     \fB-u\fP, and \fB--utf-8\fP options are specific to \fBpcregrep\fP.
365 nigel 77 .
366 nigel 87 .
367 nigel 77 .SH "OPTIONS WITH DATA"
368     .rs
369 nigel 75 .sp
370 nigel 77 There are four different ways in which an option with data can be specified.
371     If a short form option is used, the data may follow immediately, or in the next
372     command line item. For example:
373     .sp
374     -f/some/file
375     -f /some/file
376     .sp
377     If a long form option is used, the data may appear in the same command line
378 nigel 87 item, separated by an equals character, or (with one exception) it may appear
379     in the next command line item. For example:
380 nigel 77 .sp
381     --file=/some/file
382     --file /some/file
383     .sp
384 nigel 87 Note, however, that if you want to supply a file name beginning with ~ as data
385     in a shell command, and have the shell expand ~ to a home directory, you must
386     separate the file name from the option, because the shell does not treat ~
387     specially unless it is at the start of an item.
388     .P
389     The exception to the above is the \fB--colour\fP (or \fB--color\fP) option,
390     for which the data is optional. If this option does have data, it must be given
391     in the first form, using an equals character. Otherwise it will be assumed that
392     it has no data.
393 nigel 75 .
394 nigel 87 .
395 nigel 93 .SH "MATCHING ERRORS"
396 nigel 87 .rs
397     .sp
398     It is possible to supply a regular expression that takes a very long time to
399     fail to match certain lines. Such patterns normally involve nested indefinite
400     repeats, for example: (a+)*\ed when matched against a line of a's with no final
401     digit. The PCRE matching function has a resource limit that causes it to abort
402     in these circumstances. If this happens, \fBpcregrep\fP outputs an error
403     message and the line that caused the problem to the standard error stream. If
404     there are more than 20 such errors, \fBpcregrep\fP gives up.
405     .
406     .
407 nigel 49 .SH DIAGNOSTICS
408 nigel 63 .rs
409     .sp
410 nigel 49 Exit status is 0 if any matches were found, 1 if no matches were found, and 2
411 nigel 77 for syntax errors and non-existent or inacessible files (even if matches were
412 nigel 87 found in other files) or too many matching errors. Using the \fB-s\fP option to
413     suppress error messages about inaccessble files does not affect the return
414     code.
415 nigel 75 .
416     .
417 nigel 93 .SH "SEE ALSO"
418     .rs
419     .sp
420     \fBpcrepattern\fP(3), \fBpcretest\fP(1).
421     .
422     .
423 nigel 49 .SH AUTHOR
424 nigel 63 .rs
425     .sp
426 ph10 99 .nf
427 nigel 77 Philip Hazel
428 nigel 63 University Computing Service
429 nigel 93 Cambridge CB2 3QH, England.
430 ph10 99 .fi
431     .
432     .
433     .SH REVISION
434     .rs
435     .sp
436     .nf
437 ph10 286 Last updated: 17 December 2007
438 ph10 99 Copyright (c) 1997-2007 University of Cambridge.
439     .fi

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