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Load pcre-6.0 into code/trunk.
1 .TH PCREGREP 1
2 .SH NAME
3 pcregrep - a grep with Perl-compatible regular expressions.
4 .SH SYNOPSIS
5 .B pcregrep [options] [long options] [pattern] [file1 file2 ...]
6 .
7 .SH DESCRIPTION
8 .rs
9 .sp
10 \fBpcregrep\fP searches files for character patterns, in the same way as other
11 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 .\" HREF
14 \fBpcrepattern\fP
15 .\"
16 for a full description of syntax and semantics of the regular expressions that
17 PCRE supports.
18 .P
19 A pattern must be specified on the command line unless the \fB-f\fP option is
20 used (see below).
21 .P
22 If no files are specified, \fBpcregrep\fP reads the standard input. The
23 standard input can also be referenced by a name consisting of a single hyphen.
24 For example:
25 .sp
26 pcregrep some-pattern /file1 - /file3
27 .sp
28 By default, each line that matches the pattern is copied to the standard
29 output, and if there is more than one file, the file name is printed before
30 each line of output. However, there are options that can change how
31 \fBpcregrep\fP behaves. In particular, the \fB-M\fP option makes it possible to
32 search for patterns that span line boundaries.
33 .P
34 Patterns are limited to 8K or BUFSIZ characters, whichever is the greater.
35 BUFSIZ is defined in \fB<stdio.h>\fP.
36 .
37 .SH OPTIONS
38 .rs
39 .TP 10
40 \fB--\fP
41 This terminate the list of options. It is useful if the next item on the
42 command line starts with a hyphen, but is not an option.
43 .TP
44 \fB-A\fP \fInumber\fP
45 Print \fInumber\fP lines of context after each matching line. If file names
46 and/or line numbers are being printed, a hyphen separator is used instead of a
47 colon for the context lines. A line containing "--" is printed between each
48 group of lines, unless they are in fact contiguous in the input file. The value
49 of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
50 guarantees to have up to 8K of following text available for context printing.
51 .TP
52 \fB-B\fP \fInumber\fP
53 Print \fInumber\fP lines of context before each matching line. If file names
54 and/or line numbers are being printed, a hyphen separator is used instead of a
55 colon for the context lines. A line containing "--" is printed between each
56 group of lines, unless they are in fact contiguous in the input file. The value
57 of \fInumber\fP is expected to be relatively small. However, \fBpcregrep\fP
58 guarantees to have up to 8K of preceding text available for context printing.
59 .TP
60 \fB-C\fP \fInumber\fP
61 Print \fInumber\fP lines of context both before and after each matching line.
62 This is equivalent to setting both \fB-A\fP and \fB-B\fP to the same value.
63 .TP
64 \fB-c\fP
65 Do not print individual lines; instead just print a count of the number of
66 lines that would otherwise have been printed. If several files are given, a
67 count is printed for each of them.
68 .TP
69 \fB--exclude\fP=\fIpattern\fP
70 When \fBpcregrep\fP is searching the files in a directory as a consequence of
71 the \fB-r\fP (recursive search) option, any files whose names match the pattern
72 are excluded. The pattern is a PCRE regular expression. If a file name matches
73 both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no short
74 form for this option.
75 .TP
76 \fB-f\fP\fIfilename\fP
77 Read a number of patterns from the file, one per line, and match all of them
78 against each line of input. A line is output if any of the patterns match it.
79 When \fB-f\fP is used, no pattern is taken from the command line; all arguments
80 are treated as file names. There is a maximum of 100 patterns. Trailing white
81 space is removed, and blank lines are ignored. An empty file contains no
82 patterns and therefore matches nothing.
83 .TP
84 \fB-h\fP
85 Suppress printing of filenames when searching multiple files.
86 .TP
87 \fB-i\fP
88 Ignore upper/lower case distinctions during comparisons.
89 .TP
90 \fB--include\fP=\fIpattern\fP
91 When \fBpcregrep\fP is searching the files in a directory as a consequence of
92 the \fB-r\fP (recursive search) option, only files whose names match the
93 pattern are included. The pattern is a PCRE regular expression. If a file name
94 matches both \fB--include\fP and \fB--exclude\fP, it is excluded. There is no
95 short form for this option.
96 .TP
97 \fB-L\fP
98 Instead of printing lines from the files, just print the names of the files
99 that do not contain any lines that would have been printed. Each file name is
100 printed once, on a separate line.
101 .TP
102 \fB-l\fP
103 Instead of printing lines from the files, just print the names of the files
104 containing lines that would have been printed. Each file name is printed
105 once, on a separate line.
106 .TP
107 \fB--label\fP=\fIname\fP
108 This option supplies a name to be used for the standard input when file names
109 are being printed. If not supplied, "(standard input)" is used. There is no
110 short form for this option.
111 .TP
112 \fB-M\fP
113 Allow patterns to match more than one line. When this option is given, patterns
114 may usefully contain literal newline characters and internal occurrences of ^
115 and $ characters. The output for any one match may consist of more than one
116 line. When this option is set, the PCRE library is called in "multiline" mode.
117 There is a limit to the number of lines that can be matched, imposed by the way
118 that \fBpcregrep\fP buffers the input file as it scans it. However,
119 \fBpcregrep\fP ensures that at least 8K characters or the rest of the document
120 (whichever is the shorter) are available for forward matching, and similarly
121 the previous 8K characters (or all the previous characters, if fewer than 8K)
122 are guaranteed to be available for lookbehind assertions.
123 .TP
124 \fB-n\fP
125 Precede each line by its line number in the file.
126 .TP
127 \fB-q\fP
128 Work quietly, that is, display nothing except error messages.
129 The exit status indicates whether or not any matches were found.
130 .TP
131 \fB-r\fP
132 If any given path is a directory, recursively scan the files it contains,
133 taking note of any \fB--include\fP and \fB--exclude\fP settings. Without
134 \fB-r\fP a directory is scanned as a normal file.
135 .TP
136 \fB-s\fP
137 Suppress error messages about non-existent or unreadable files. Such files are
138 quietly skipped. However, the return code is still 2, even if matches were
139 found in other files.
140 .TP
141 \fB-u\fP
142 Operate in UTF-8 mode. This option is available only if PCRE has been compiled
143 with UTF-8 support. Both the pattern and each subject line must be valid
144 strings of UTF-8 characters.
145 .TP
146 \fB-V\fP
147 Write the version numbers of \fBpcregrep\fP and the PCRE library that is being
148 used to the standard error stream.
149 .TP
150 \fB-v\fP
151 Invert the sense of the match, so that lines which do \fInot\fP match the
152 pattern are the ones that are found.
153 .TP
154 \fB-w\fP
155 Force the pattern to match only whole words. This is equivalent to having \eb
156 at the start and end of the pattern.
157 .TP
158 \fB-x\fP
159 Force the pattern to be anchored (it must start matching at the beginning of
160 the line) and in addition, require it to match the entire line. This is
161 equivalent to having ^ and $ characters at the start and end of each
162 alternative branch in the regular expression.
163 .
164 .SH "LONG OPTIONS"
165 .rs
166 .sp
167 Long forms of all the options are available, as in GNU grep. They are shown in
168 the following table:
169 .sp
170 -A --after-context
171 -B --before-context
172 -C --context
173 -c --count
174 --exclude (no short form)
175 -f --file
176 -h --no-filename
177 --help (no short form)
178 -i --ignore-case
179 --include (no short form)
180 -L --files-without-match
181 -l --files-with-matches
182 --label (no short form)
183 -n --line-number
184 -r --recursive
185 -q --quiet
186 -s --no-messages
187 -u --utf-8
188 -V --version
189 -v --invert-match
190 -x --line-regex
191 -x --line-regexp
192 .
193 .SH "OPTIONS WITH DATA"
194 .rs
195 .sp
196 There are four different ways in which an option with data can be specified.
197 If a short form option is used, the data may follow immediately, or in the next
198 command line item. For example:
199 .sp
200 -f/some/file
201 -f /some/file
202 .sp
203 If a long form option is used, the data may appear in the same command line
204 item, separated by an = character, or it may appear in the next command line
205 item. For example:
206 .sp
207 --file=/some/file
208 --file /some/file
209 .sp
210 .
211 .SH DIAGNOSTICS
212 .rs
213 .sp
214 Exit status is 0 if any matches were found, 1 if no matches were found, and 2
215 for syntax errors and non-existent or inacessible files (even if matches were
216 found in other files). Using the \fB-s\fP option to suppress error messages
217 about inaccessble files does not affect the return code.
218 .
219 .
220 .SH AUTHOR
221 .rs
222 .sp
223 Philip Hazel
224 .br
225 University Computing Service
226 .br
227 Cambridge CB2 3QG, England.
228 .P
229 .in 0
230 Last updated: 16 May 2005
231 .br
232 Copyright (c) 1997-2005 University of Cambridge.

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