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revision 77 by nigel, Sat Feb 24 21:40:45 2007 UTC revision 91 by nigel, Sat Feb 24 21:41:34 2007 UTC
# Line 2  Line 2 
2  .SH NAME  .SH NAME
3  pcregrep - a grep with Perl-compatible regular expressions.  pcregrep - a grep with Perl-compatible regular expressions.
4  .SH SYNOPSIS  .SH SYNOPSIS
5  .B pcregrep [options] [long options] [pattern] [file1 file2 ...]  .B pcregrep [options] [long options] [pattern] [path1 path2 ...]
6  .  .
7  .SH DESCRIPTION  .SH DESCRIPTION
8  .rs  .rs
# Line 16  patterns that are compatible with the re Line 16  patterns that are compatible with the re
16  for a full description of syntax and semantics of the regular expressions that  for a full description of syntax and semantics of the regular expressions that
17  PCRE supports.  PCRE supports.
18  .P  .P
19  A pattern must be specified on the command line unless the \fB-f\fP option is  Patterns, whether supplied on the command line or in a separate file, are given
20  used (see below).  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    .P
30    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  .P
36  If no files are specified, \fBpcregrep\fP reads the standard input. The  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.  standard input can also be referenced by a name consisting of a single hyphen.
# Line 26  For example: Line 40  For example:
40    pcregrep some-pattern /file1 - /file3    pcregrep some-pattern /file1 - /file3
41  .sp  .sp
42  By default, each line that matches the pattern is copied to the standard  By default, each line that matches the pattern is copied to the standard
43  output, and if there is more than one file, the file name is printed before  output, and if there is more than one file, the file name is output at the
44  each line of output. However, there are options that can change how  start of each line. However, there are options that can change how
45  \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it possible to  \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it possible to
46  search for patterns that span line boundaries.  search for patterns that span line boundaries. What defines a line boundary is
47    controlled by the \fB-N\fP (\fB--newline\fP) option.
48  .P  .P
49  Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.  Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
50  BUFSIZ is defined in \fB<stdio.h>\fP.  BUFSIZ is defined in \fB<stdio.h>\fP.
51    .P
52    If the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variable is set,
53    \fBpcregrep\fP uses the value to set a locale when calling the PCRE library.
54    The \fB--locale\fP option can be used to override this.
55  .  .
56  .SH OPTIONS  .SH OPTIONS
57  .rs  .rs
58  .TP 10  .TP 10
59  \fB--\fP  \fB--\fP
60  This terminate the list of options. It is useful if the next item on the  This terminate the list of options. It is useful if the next item on the
61  command line starts with a hyphen, but is not an option.  command line starts with a hyphen but is not an option. This allows for the
62    processing of patterns and filenames that start with hyphens.
63  .TP  .TP
64  \fB-A\fP \fInumber\fP  \fB-A\fP \fInumber\fP, \fB--after-context=\fP\fInumber\fP
65  Print \fInumber\fP lines of context after each matching line. If file names  Output \fInumber\fP lines of context after each matching line. If filenames
66  and/or line numbers are being printed, a hyphen separator is used instead of a  and/or line numbers are being output, a hyphen separator is used instead of a
67  colon for the context lines. A line containing "--" is printed between each  colon for the context lines. A line containing "--" is output between each
68  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
69  of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP  of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
70  guarantees to have up to 8K of following text available for context printing.  guarantees to have up to 8K of following text available for context output.
71  .TP  .TP
72  \fB-B\fP \fInumber\fP  \fB-B\fP \fInumber\fP, \fB--before-context=\fP\fInumber\fP
73  Print \fInumber\fP lines of context before each matching line. If file names  Output \fInumber\fP lines of context before each matching line. If filenames
74  and/or line numbers are being printed, a hyphen separator is used instead of a  and/or line numbers are being output, a hyphen separator is used instead of a
75  colon for the context lines. A line containing "--" is printed between each  colon for the context lines. A line containing "--" is output between each
76  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
77  of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP  of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
78  guarantees to have up to 8K of preceding text available for context printing.  guarantees to have up to 8K of preceding text available for context output.
79  .TP  .TP
80  \fB-C\fP \fInumber\fP  \fB-C\fP \fInumber\fP, \fB--context=\fP\fInumber\fP
81  Print \fInumber\fP lines of context both before and after each matching line.  Output \fInumber\fP lines of context both before and after each matching line.
82  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.
83  .TP  .TP
84  \fB-c\fP  \fB-c\fP, \fB--count\fP
85  Do not print individual lines; instead just print a count of the number of  Do not output individual lines; instead just output a count of the number of
86  lines that would otherwise have been printed. If several files are given, a  lines that would otherwise have been output. If several files are given, a
87  count is printed for each of them.  count is output for each of them. In this mode, the \fB-A\fP, \fB-B\fP, and
88    \fB-C\fP options are ignored.
89    .TP
90    \fB--colour\fP, \fB--color\fP
91    If this option is given without any data, it is equivalent to "--colour=auto".
92    If data is required, it must be given in the same shell item, separated by an
93    equals sign.
94    .TP
95    \fB--colour=\fP\fIvalue\fP, \fB--color=\fP\fIvalue\fP
96    This option specifies under what circumstances the part of a line that matched
97    a pattern should be coloured in the output. The value may be "never" (the
98    default), "always", or "auto". In the latter case, colouring happens only if
99    the standard output is connected to a terminal. The colour can be specified by
100    setting the environment variable PCREGREP_COLOUR or PCREGREP_COLOR. The value
101    of this variable should be a string of two numbers, separated by a semicolon.
102    They are copied directly into the control string for setting colour on a
103    terminal, so it is your responsibility to ensure that they make sense. If
104    neither of the environment variables is set, the default is "1;31", which gives
105    red.
106    .TP
107    \fB-D\fP \fIaction\fP, \fB--devices=\fP\fIaction\fP
108    If an input path is not a regular file or a directory, "action" specifies how
109    it is to be processed. Valid values are "read" (the default) or "skip"
110    (silently skip the path).
111    .TP
112    \fB-d\fP \fIaction\fP, \fB--directories=\fP\fIaction\fP
113    If an input path is a directory, "action" specifies how it is to be processed.
114    Valid values are "read" (the default), "recurse" (equivalent to the \fB-r\fP
115    option), or "skip" (silently skip the path). In the default case, directories
116    are read as if they were ordinary files. In some operating systems the effect
117    of reading a directory like this is an immediate end-of-file.
118    .TP
119    \fB-e\fP \fIpattern\fP, \fB--regex=\fP\fIpattern\fP,
120    \fB--regexp=\fP\fIpattern\fP Specify a pattern to be matched. This option can
121    be used multiple times in order to specify several patterns. It can also be
122    used as a way of specifying a single pattern that starts with a hyphen. When
123    \fB-e\fP is used, no argument pattern is taken from the command line; all
124    arguments are treated as file names. There is an overall maximum of 100
125    patterns. They are applied to each line in the order in which they are defined
126    until one matches (or fails to match if \fB-v\fP is used). If \fB-f\fP is used
127    with \fB-e\fP, the command line patterns are matched first, followed by the
128    patterns from the file, independent of the order in which these options are
129    specified. Note that multiple use of \fB-e\fP is not the same as a single
130    pattern with alternatives. For example, X|Y finds the first character in a line
131    that is X or Y, whereas if the two patterns are given separately,
132    \fBpcregrep\fP finds X if it is present, even if it follows Y in the line. It
133    finds Y only if there is no X in the line. This really matters only if you are
134    using \fB-o\fP to show the portion of the line that matched.
135  .TP  .TP
136  \fB--exclude\fP=\fIpattern\fP  \fB--exclude\fP=\fIpattern\fP
137  When \fBpcregrep\fP is searching the files in a directory as a consequence of  When \fBpcregrep\fP is searching the files in a directory as a consequence of
# Line 73  are excluded. The pattern is a PCRE regu Line 140  are excluded. The pattern is a PCRE regu
140  both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short  both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
141  form for this option.  form for this option.
142  .TP  .TP
143  \fB-f\fP\fIfilename\fP  \fB-F\fP, \fB--fixed-strings\fP
144  Read a number of patterns from the file, one per line, and match all of them  Interpret each pattern as a list of fixed strings, separated by newlines,
145  against each line of input. A line is output if any of the patterns match it.  instead of as a regular expression. The \fB-w\fP (match as a word) and \fB-x\fP
146  When \fB-f\fP is used, no pattern is taken from the command line; all arguments  (match whole line) options can be used with \fB-F\fP. They apply to each of the
147  are treated as file names. There is a maximum of 100 patterns. Trailing white  fixed strings. A line is selected if any of the fixed strings are found in it
148  space is removed, and blank lines are ignored. An empty file contains no  (subject to \fB-w\fP or \fB-x\fP, if present).
149  patterns and therefore matches nothing.  .TP
150    \fB-f\fP \fIfilename\fP, \fB--file=\fP\fIfilename\fP
151    Read a number of patterns from the file, one per line, and match them against
152    each line of input. A data line is output if any of the patterns match it. The
153    filename can be given as "-" to refer to the standard input. When \fB-f\fP is
154    used, patterns specified on the command line using \fB-e\fP may also be
155    present; they are tested before the file's patterns. However, no other pattern
156    is taken from the command line; all arguments are treated as file names. There
157    is an overall maximum of 100 patterns. Trailing white space is removed from
158    each line, and blank lines are ignored. An empty file contains no patterns and
159    therefore matches nothing.
160    .TP
161    \fB-H\fP, \fB--with-filename\fP
162    Force the inclusion of the filename at the start of output lines when searching
163    a single file. By default, the filename is not shown in this case. For matching
164    lines, the filename is followed by a colon and a space; for context lines, a
165    hyphen separator is used. If a line number is also being output, it follows the
166    file name without a space.
167    .TP
168    \fB-h\fP, \fB--no-filename\fP
169    Suppress the output filenames when searching multiple files. By default,
170    filenames are shown when multiple files are searched. For matching lines, the
171    filename is followed by a colon and a space; for context lines, a hyphen
172    separator is used. If a line number is also being output, it follows the file
173    name without a space.
174  .TP  .TP
175  \fB-h\fP  \fB--help\fP
176  Suppress printing of filenames when searching multiple files.  Output a brief help message and exit.
177  .TP  .TP
178  \fB-i\fP  \fB-i\fP, \fB--ignore-case\fP
179  Ignore upper/lower case distinctions during comparisons.  Ignore upper/lower case distinctions during comparisons.
180  .TP  .TP
181  \fB--include\fP=\fIpattern\fP  \fB--include\fP=\fIpattern\fP
182  When \fBpcregrep\fP is searching the files in a directory as a consequence of  When \fBpcregrep\fP is searching the files in a directory as a consequence of
183  the \fB-r\fP (recursive search) option, only files whose names match the  the \fB-r\fP (recursive search) option, only those files whose names match the
184  pattern are included. The pattern is a PCRE regular expression. If a file name  pattern are included. The pattern is a PCRE regular expression. If a file name
185  matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no  matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no
186  short form for this option.  short form for this option.
187  .TP  .TP
188  \fB-L\fP  \fB-L\fP, \fB--files-without-match\fP
189  Instead of printing lines from the files, just print the names of the files  Instead of outputting lines from the files, just output the names of the files
190  that do not contain any lines that would have been printed. Each file name is  that do not contain any lines that would have been output. Each file name is
191  printed once, on a separate line.  output once, on a separate line.
192  .TP  .TP
193  \fB-l\fP  \fB-l\fP, \fB--files-with-matches\fP
194  Instead of printing lines from the files, just print the names of the files  Instead of outputting lines from the files, just output the names of the files
195  containing lines that would have been printed. Each file name is printed  containing lines that would have been output. Each file name is output
196  once, on a separate line.  once, on a separate line. Searching stops as soon as a matching line is found
197    in a file.
198  .TP  .TP
199  \fB--label\fP=\fIname\fP  \fB--label\fP=\fIname\fP
200  This option supplies a name to be used for the standard input when file names  This option supplies a name to be used for the standard input when file names
201  are being printed. If not supplied, "(standard input)" is used. There is no  are being output. If not supplied, "(standard input)" is used. There is no
202  short form for this option.  short form for this option.
203  .TP  .TP
204  \fB-M\fP  \fB--locale\fP=\fIlocale-name\fP
205    This option specifies a locale to be used for pattern matching. It overrides
206    the value in the \fBLC_ALL\fP or \fBLC_CTYPE\fP environment variables. If no
207    locale is specified, the PCRE library's default (usually the "C" locale) is
208    used. There is no short form for this option.
209    .TP
210    \fB-M\fP, \fB--multiline\fP
211  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
212  may usefully contain literal newline characters and internal occurrences of ^  may usefully contain literal newline characters and internal occurrences of ^
213  and $ characters. The output for any one match may consist of more than one  and $ characters. The output for any one match may consist of more than one
# Line 121  that \fBpcregrep\fP buffers the input fi Line 219  that \fBpcregrep\fP buffers the input fi
219  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)
220  are guaranteed to be available for lookbehind assertions.  are guaranteed to be available for lookbehind assertions.
221  .TP  .TP
222  \fB-n\fP  \fB-N\fP \fInewline-type\fP, \fB--newline=\fP\fInewline-type\fP
223  Precede each line by its line number in the file.  The PCRE library supports three different character sequences for indicating
224  .TP  the ends of lines. They are the single-character sequences CR (carriage return)
225  \fB-q\fP  and LF (linefeed), and the two-character sequence CR, LF. When the library is
226  Work quietly, that is, display nothing except error messages.  built, a default line-ending sequence is specified. This is normally the
227  The exit status indicates whether or not any matches were found.  standard sequence for the operating system. Unless otherwise specified by this
228    option, \fBpcregrep\fP uses the default. The possible values for this option
229    are CR, LF, or CRLF. This makes it possible to use \fBpcregrep\fP on files that
230    have come from other environments without having to modify their line endings.
231    If the data that is being scanned does not agree with the convention set by
232    this option, \fBpcregrep\fP may behave in strange ways.
233    .TP
234    \fB-n\fP, \fB--line-number\fP
235    Precede each output line by its line number in the file, followed by a colon
236    and a space for matching lines or a hyphen and a space for context lines. If
237    the filename is also being output, it precedes the line number.
238    .TP
239    \fB-o\fP, \fB--only-matching\fP
240    Show only the part of the line that matched a pattern. In this mode, no
241    context is shown. That is, the \fB-A\fP, \fB-B\fP, and \fB-C\fP options are
242    ignored.
243    .TP
244    \fB-q\fP, \fB--quiet\fP
245    Work quietly, that is, display nothing except error messages. The exit
246    status indicates whether or not any matches were found.
247  .TP  .TP
248  \fB-r\fP  \fB-r\fP, \fB--recursive\fP
249  If any given path is a directory, recursively scan the files it contains,  If any given path is a directory, recursively scan the files it contains,
250  taking note of any \fB--include\fP and \fB--exclude\fP settings. Without  taking note of any \fB--include\fP and \fB--exclude\fP settings. By default, a
251  \fB-r\fP a directory is scanned as a normal file.  directory is read as a normal file; in some operating systems this gives an
252    immediate end-of-file. This option is a shorthand for setting the \fB-d\fP
253    option to "recurse".
254  .TP  .TP
255  \fB-s\fP  \fB-s\fP, \fB--no-messages\fP
256  Suppress error messages about non-existent or unreadable files. Such files are  Suppress error messages about non-existent or unreadable files. Such files are
257  quietly skipped. However, the return code is still 2, even if matches were  quietly skipped. However, the return code is still 2, even if matches were
258  found in other files.  found in other files.
259  .TP  .TP
260  \fB-u\fP  \fB-u\fP, \fB--utf-8\fP
261  Operate in UTF-8 mode. This option is available only if PCRE has been compiled  Operate in UTF-8 mode. This option is available only if PCRE has been compiled
262  with UTF-8 support. Both the pattern and each subject line must be valid  with UTF-8 support. Both patterns and subject lines must be valid strings of
263  strings of UTF-8 characters.  UTF-8 characters.
264  .TP  .TP
265  \fB-V\fP  \fB-V\fP, \fB--version\fP
266  Write the version numbers of \fBpcregrep\fP and the PCRE library that is being  Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
267  used to the standard error stream.  used to the standard error stream.
268  .TP  .TP
269  \fB-v\fP  \fB-v\fP, \fB--invert-match\fP
270  Invert the sense of the match, so that lines which do \fInot\fP match the  Invert the sense of the match, so that lines which do \fInot\fP match any of
271  pattern are the ones that are found.  the patterns are the ones that are found.
272  .TP  .TP
273  \fB-w\fP  \fB-w\fP, \fB--word-regex\fP, \fB--word-regexp\fP
274  Force the pattern to match only whole words. This is equivalent to having \eb  Force the patterns to match only whole words. This is equivalent to having \eb
275  at the start and end of the pattern.  at the start and end of the pattern.
276  .TP  .TP
277  \fB-x\fP  \fB-x\fP, \fB--line-regex\fP, \fP--line-regexp\fP
278  Force the pattern to be anchored (it must start matching at the beginning of  Force the patterns to be anchored (each must start matching at the beginning of
279  the line) and in addition, require it to match the entire line. This is  a line) and in addition, require them to match entire lines. This is
280  equivalent to having ^ and $ characters at the start and end of each  equivalent to having ^ and $ characters at the start and end of each
281  alternative branch in the regular expression.  alternative branch in every pattern.
282  .  .
283  .SH "LONG OPTIONS"  .
284    .SH "ENVIRONMENT VARIABLES"
285  .rs  .rs
286  .sp  .sp
287  Long forms of all the options are available, as in GNU grep. They are shown in  The environment variables \fBLC_ALL\fP and \fBLC_CTYPE\fP are examined, in that
288  the following table:  order, for a locale. The first one that is set is used. This can be overridden
289    by the \fB--locale\fP option. If no locale is set, the PCRE library's default
290    (usually the "C" locale) is used.
291    .
292    .
293    .SH "NEWLINES"
294    .rs
295  .sp  .sp
296    -A   --after-context  The \fB-N\fP (\fB--newline\fP) option allows \fBpcregrep\fP to scan files with
297    -B   --before-context  different newline conventions from the default. However, the setting of this
298    -C   --context  option does not affect the way in which \fBpcregrep\fP writes information to
299    -c   --count  the standard error and output streams. It uses the string "\en" in C
300         --exclude (no short form)  \fBprintf()\fP calls to indicate newlines, relying on the C I/O library to
301    -f   --file  convert this to an appropriate sequence if the output is sent to a file.
302    -h   --no-filename  .
303         --help (no short form)  .
304    -i   --ignore-case  .SH "OPTIONS COMPATIBILITY"
305         --include (no short form)  .rs
306    -L   --files-without-match  .sp
307    -l   --files-with-matches  The majority of short and long forms of \fBpcregrep\fP's options are the same
308         --label (no short form)  as in the GNU \fBgrep\fP program. Any long option of the form
309    -n   --line-number  \fB--xxx-regexp\fP (GNU terminology) is also available as \fB--xxx-regex\fP
310    -r   --recursive  (PCRE terminology). However, the \fB--locale\fP, \fB-M\fP, \fB--multiline\fP,
311    -q   --quiet  \fB-u\fP, and \fB--utf-8\fP options are specific to \fBpcregrep\fP.
312    -s   --no-messages  .
   -u   --utf-8  
   -V   --version  
   -v   --invert-match  
   -x   --line-regex  
   -x   --line-regexp  
313  .  .
314  .SH "OPTIONS WITH DATA"  .SH "OPTIONS WITH DATA"
315  .rs  .rs
# Line 201  command line item. For example: Line 322  command line item. For example:
322    -f /some/file    -f /some/file
323  .sp  .sp
324  If a long form option is used, the data may appear in the same command line  If a long form option is used, the data may appear in the same command line
325  item, separated by an = character, or it may appear in the next command line  item, separated by an equals character, or (with one exception) it may appear
326  item. For example:  in the next command line item. For example:
327  .sp  .sp
328    --file=/some/file    --file=/some/file
329    --file /some/file    --file /some/file
330  .sp  .sp
331    Note, however, that if you want to supply a file name beginning with ~ as data
332    in a shell command, and have the shell expand ~ to a home directory, you must
333    separate the file name from the option, because the shell does not treat ~
334    specially unless it is at the start of an item.
335    .P
336    The exception to the above is the \fB--colour\fP (or \fB--color\fP) option,
337    for which the data is optional. If this option does have data, it must be given
338    in the first form, using an equals character. Otherwise it will be assumed that
339    it has no data.
340    .
341    .
342    .SH MATCHING ERRORS
343    .rs
344    .sp
345    It is possible to supply a regular expression that takes a very long time to
346    fail to match certain lines. Such patterns normally involve nested indefinite
347    repeats, for example: (a+)*\ed when matched against a line of a's with no final
348    digit. The PCRE matching function has a resource limit that causes it to abort
349    in these circumstances. If this happens, \fBpcregrep\fP outputs an error
350    message and the line that caused the problem to the standard error stream. If
351    there are more than 20 such errors, \fBpcregrep\fP gives up.
352    .
353  .  .
354  .SH DIAGNOSTICS  .SH DIAGNOSTICS
355  .rs  .rs
356  .sp  .sp
357  Exit status is 0 if any matches were found, 1 if no matches were found, and 2  Exit status is 0 if any matches were found, 1 if no matches were found, and 2
358  for syntax errors and non-existent or inacessible files (even if matches were  for syntax errors and non-existent or inacessible files (even if matches were
359  found in other files). Using the \fB-s\fP option to suppress error messages  found in other files) or too many matching errors. Using the \fB-s\fP option to
360  about inaccessble files does not affect the return code.  suppress error messages about inaccessble files does not affect the return
361    code.
362  .  .
363  .  .
364  .SH AUTHOR  .SH AUTHOR
# Line 227  University Computing Service Line 371  University Computing Service
371  Cambridge CB2 3QG, England.  Cambridge CB2 3QG, England.
372  .P  .P
373  .in 0  .in 0
374  Last updated: 16 May 2005  Last updated: 06 June 2006
375  .br  .br
376  Copyright (c) 1997-2005 University of Cambridge.  Copyright (c) 1997-2006 University of Cambridge.

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