Annotation of embedaddon/pcre/doc/html/pcregrep.html, revision 1.1.1.1
1.1 misho 1: <html>
2: <head>
3: <title>pcregrep specification</title>
4: </head>
5: <body bgcolor="#FFFFFF" text="#00005A" link="#0066FF" alink="#3399FF" vlink="#2222BB">
6: <h1>pcregrep man page</h1>
7: <p>
8: Return to the <a href="index.html">PCRE index page</a>.
9: </p>
10: <p>
11: This page is part of the PCRE HTML documentation. It was generated automatically
12: from the original man page. If there is any nonsense in it, please consult the
13: man page, in case the conversion went wrong.
14: <br>
15: <ul>
16: <li><a name="TOC1" href="#SEC1">SYNOPSIS</a>
17: <li><a name="TOC2" href="#SEC2">DESCRIPTION</a>
18: <li><a name="TOC3" href="#SEC3">SUPPORT FOR COMPRESSED FILES</a>
19: <li><a name="TOC4" href="#SEC4">OPTIONS</a>
20: <li><a name="TOC5" href="#SEC5">ENVIRONMENT VARIABLES</a>
21: <li><a name="TOC6" href="#SEC6">NEWLINES</a>
22: <li><a name="TOC7" href="#SEC7">OPTIONS COMPATIBILITY</a>
23: <li><a name="TOC8" href="#SEC8">OPTIONS WITH DATA</a>
24: <li><a name="TOC9" href="#SEC9">MATCHING ERRORS</a>
25: <li><a name="TOC10" href="#SEC10">DIAGNOSTICS</a>
26: <li><a name="TOC11" href="#SEC11">SEE ALSO</a>
27: <li><a name="TOC12" href="#SEC12">AUTHOR</a>
28: <li><a name="TOC13" href="#SEC13">REVISION</a>
29: </ul>
30: <br><a name="SEC1" href="#TOC1">SYNOPSIS</a><br>
31: <P>
32: <b>pcregrep [options] [long options] [pattern] [path1 path2 ...]</b>
33: </P>
34: <br><a name="SEC2" href="#TOC1">DESCRIPTION</a><br>
35: <P>
36: <b>pcregrep</b> searches files for character patterns, in the same way as other
37: grep commands do, but it uses the PCRE regular expression library to support
38: patterns that are compatible with the regular expressions of Perl 5. See
39: <a href="pcrepattern.html"><b>pcrepattern</b>(3)</a>
40: for a full description of syntax and semantics of the regular expressions
41: that PCRE supports.
42: </P>
43: <P>
44: Patterns, whether supplied on the command line or in a separate file, are given
45: without delimiters. For example:
46: <pre>
47: pcregrep Thursday /etc/motd
48: </pre>
49: If you attempt to use delimiters (for example, by surrounding a pattern with
50: slashes, as is common in Perl scripts), they are interpreted as part of the
51: pattern. Quotes can of course be used to delimit patterns on the command line
52: because they are interpreted by the shell, and indeed they are required if a
53: pattern contains white space or shell metacharacters.
54: </P>
55: <P>
56: The first argument that follows any option settings is treated as the single
57: pattern to be matched when neither <b>-e</b> nor <b>-f</b> is present.
58: Conversely, when one or both of these options are used to specify patterns, all
59: arguments are treated as path names. At least one of <b>-e</b>, <b>-f</b>, or an
60: argument pattern must be provided.
61: </P>
62: <P>
63: If no files are specified, <b>pcregrep</b> reads the standard input. The
64: standard input can also be referenced by a name consisting of a single hyphen.
65: For example:
66: <pre>
67: pcregrep some-pattern /file1 - /file3
68: </pre>
69: By default, each line that matches a pattern is copied to the standard
70: output, and if there is more than one file, the file name is output at the
71: start of each line, followed by a colon. However, there are options that can
72: change how <b>pcregrep</b> behaves. In particular, the <b>-M</b> option makes it
73: possible to search for patterns that span line boundaries. What defines a line
74: boundary is controlled by the <b>-N</b> (<b>--newline</b>) option.
75: </P>
76: <P>
77: The amount of memory used for buffering files that are being scanned is
78: controlled by a parameter that can be set by the <b>--buffer-size</b> option.
79: The default value for this parameter is specified when <b>pcregrep</b> is built,
80: with the default default being 20K. A block of memory three times this size is
81: used (to allow for buffering "before" and "after" lines). An error occurs if a
82: line overflows the buffer.
83: </P>
84: <P>
85: Patterns are limited to 8K or BUFSIZ bytes, whichever is the greater. BUFSIZ is
86: defined in <b><stdio.h></b>. When there is more than one pattern (specified by
87: the use of <b>-e</b> and/or <b>-f</b>), each pattern is applied to each line in
88: the order in which they are defined, except that all the <b>-e</b> patterns are
89: tried before the <b>-f</b> patterns.
90: </P>
91: <P>
92: By default, as soon as one pattern matches (or fails to match when <b>-v</b> is
93: used), no further patterns are considered. However, if <b>--colour</b> (or
94: <b>--color</b>) is used to colour the matching substrings, or if
95: <b>--only-matching</b>, <b>--file-offsets</b>, or <b>--line-offsets</b> is used to
96: output only the part of the line that matched (either shown literally, or as an
97: offset), scanning resumes immediately following the match, so that further
98: matches on the same line can be found. If there are multiple patterns, they are
99: all tried on the remainder of the line, but patterns that follow the one that
100: matched are not tried on the earlier part of the line.
101: </P>
102: <P>
103: This is the same behaviour as GNU grep, but it does mean that the order in
104: which multiple patterns are specified can affect the output when one of the
105: above options is used.
106: </P>
107: <P>
108: Patterns that can match an empty string are accepted, but empty string
109: matches are never recognized. An example is the pattern "(super)?(man)?", in
110: which all components are optional. This pattern finds all occurrences of both
111: "super" and "man"; the output differs from matching with "super|man" when only
112: the matching substrings are being shown.
113: </P>
114: <P>
115: If the <b>LC_ALL</b> or <b>LC_CTYPE</b> environment variable is set,
116: <b>pcregrep</b> uses the value to set a locale when calling the PCRE library.
117: The <b>--locale</b> option can be used to override this.
118: </P>
119: <br><a name="SEC3" href="#TOC1">SUPPORT FOR COMPRESSED FILES</a><br>
120: <P>
121: It is possible to compile <b>pcregrep</b> so that it uses <b>libz</b> or
122: <b>libbz2</b> to read files whose names end in <b>.gz</b> or <b>.bz2</b>,
123: respectively. You can find out whether your binary has support for one or both
124: of these file types by running it with the <b>--help</b> option. If the
125: appropriate support is not present, files are treated as plain text. The
126: standard input is always so treated.
127: </P>
128: <br><a name="SEC4" href="#TOC1">OPTIONS</a><br>
129: <P>
130: The order in which some of the options appear can affect the output. For
131: example, both the <b>-h</b> and <b>-l</b> options affect the printing of file
132: names. Whichever comes later in the command line will be the one that takes
133: effect. Numerical values for options may be followed by K or M, to signify
134: multiplication by 1024 or 1024*1024 respectively.
135: </P>
136: <P>
137: <b>--</b>
138: This terminates the list of options. It is useful if the next item on the
139: command line starts with a hyphen but is not an option. This allows for the
140: processing of patterns and filenames that start with hyphens.
141: </P>
142: <P>
143: <b>-A</b> <i>number</i>, <b>--after-context=</b><i>number</i>
144: Output <i>number</i> lines of context after each matching line. If filenames
145: and/or line numbers are being output, a hyphen separator is used instead of a
146: colon for the context lines. A line containing "--" is output between each
147: group of lines, unless they are in fact contiguous in the input file. The value
148: of <i>number</i> is expected to be relatively small. However, <b>pcregrep</b>
149: guarantees to have up to 8K of following text available for context output.
150: </P>
151: <P>
152: <b>-B</b> <i>number</i>, <b>--before-context=</b><i>number</i>
153: Output <i>number</i> lines of context before each matching line. If filenames
154: and/or line numbers are being output, a hyphen separator is used instead of a
155: colon for the context lines. A line containing "--" is output between each
156: group of lines, unless they are in fact contiguous in the input file. The value
157: of <i>number</i> is expected to be relatively small. However, <b>pcregrep</b>
158: guarantees to have up to 8K of preceding text available for context output.
159: </P>
160: <P>
161: <b>--buffer-size=</b><i>number</i>
162: Set the parameter that controls how much memory is used for buffering files
163: that are being scanned.
164: </P>
165: <P>
166: <b>-C</b> <i>number</i>, <b>--context=</b><i>number</i>
167: Output <i>number</i> lines of context both before and after each matching line.
168: This is equivalent to setting both <b>-A</b> and <b>-B</b> to the same value.
169: </P>
170: <P>
171: <b>-c</b>, <b>--count</b>
172: Do not output individual lines from the files that are being scanned; instead
173: output the number of lines that would otherwise have been shown. If no lines
174: are selected, the number zero is output. If several files are are being
175: scanned, a count is output for each of them. However, if the
176: <b>--files-with-matches</b> option is also used, only those files whose counts
177: are greater than zero are listed. When <b>-c</b> is used, the <b>-A</b>,
178: <b>-B</b>, and <b>-C</b> options are ignored.
179: </P>
180: <P>
181: <b>--colour</b>, <b>--color</b>
182: If this option is given without any data, it is equivalent to "--colour=auto".
183: If data is required, it must be given in the same shell item, separated by an
184: equals sign.
185: </P>
186: <P>
187: <b>--colour=</b><i>value</i>, <b>--color=</b><i>value</i>
188: This option specifies under what circumstances the parts of a line that matched
189: a pattern should be coloured in the output. By default, the output is not
190: coloured. The value (which is optional, see above) may be "never", "always", or
191: "auto". In the latter case, colouring happens only if the standard output is
192: connected to a terminal. More resources are used when colouring is enabled,
193: because <b>pcregrep</b> has to search for all possible matches in a line, not
194: just one, in order to colour them all.
195: <br>
196: <br>
197: The colour that is used can be specified by setting the environment variable
198: PCREGREP_COLOUR or PCREGREP_COLOR. The value of this variable should be a
199: string of two numbers, separated by a semicolon. They are copied directly into
200: the control string for setting colour on a terminal, so it is your
201: responsibility to ensure that they make sense. If neither of the environment
202: variables is set, the default is "1;31", which gives red.
203: </P>
204: <P>
205: <b>-D</b> <i>action</i>, <b>--devices=</b><i>action</i>
206: If an input path is not a regular file or a directory, "action" specifies how
207: it is to be processed. Valid values are "read" (the default) or "skip"
208: (silently skip the path).
209: </P>
210: <P>
211: <b>-d</b> <i>action</i>, <b>--directories=</b><i>action</i>
212: If an input path is a directory, "action" specifies how it is to be processed.
213: Valid values are "read" (the default), "recurse" (equivalent to the <b>-r</b>
214: option), or "skip" (silently skip the path). In the default case, directories
215: are read as if they were ordinary files. In some operating systems the effect
216: of reading a directory like this is an immediate end-of-file.
217: </P>
218: <P>
219: <b>-e</b> <i>pattern</i>, <b>--regex=</b><i>pattern</i>, <b>--regexp=</b><i>pattern</i>
220: Specify a pattern to be matched. This option can be used multiple times in
221: order to specify several patterns. It can also be used as a way of specifying a
222: single pattern that starts with a hyphen. When <b>-e</b> is used, no argument
223: pattern is taken from the command line; all arguments are treated as file
224: names. There is an overall maximum of 100 patterns. They are applied to each
225: line in the order in which they are defined until one matches (or fails to
226: match if <b>-v</b> is used). If <b>-f</b> is used with <b>-e</b>, the command line
227: patterns are matched first, followed by the patterns from the file, independent
228: of the order in which these options are specified. Note that multiple use of
229: <b>-e</b> is not the same as a single pattern with alternatives. For example,
230: X|Y finds the first character in a line that is X or Y, whereas if the two
231: patterns are given separately, <b>pcregrep</b> finds X if it is present, even if
232: it follows Y in the line. It finds Y only if there is no X in the line. This
233: really matters only if you are using <b>-o</b> to show the part(s) of the line
234: that matched.
235: </P>
236: <P>
237: <b>--exclude</b>=<i>pattern</i>
238: When <b>pcregrep</b> is searching the files in a directory as a consequence of
239: the <b>-r</b> (recursive search) option, any regular files whose names match the
240: pattern are excluded. Subdirectories are not excluded by this option; they are
241: searched recursively, subject to the <b>--exclude-dir</b> and
242: <b>--include_dir</b> options. The pattern is a PCRE regular expression, and is
243: matched against the final component of the file name (not the entire path). If
244: a file name matches both <b>--include</b> and <b>--exclude</b>, it is excluded.
245: There is no short form for this option.
246: </P>
247: <P>
248: <b>--exclude-dir</b>=<i>pattern</i>
249: When <b>pcregrep</b> is searching the contents of a directory as a consequence
250: of the <b>-r</b> (recursive search) option, any subdirectories whose names match
251: the pattern are excluded. (Note that the \fP--exclude\fP option does not affect
252: subdirectories.) The pattern is a PCRE regular expression, and is matched
253: against the final component of the name (not the entire path). If a
254: subdirectory name matches both <b>--include-dir</b> and <b>--exclude-dir</b>, it
255: is excluded. There is no short form for this option.
256: </P>
257: <P>
258: <b>-F</b>, <b>--fixed-strings</b>
259: Interpret each pattern as a list of fixed strings, separated by newlines,
260: instead of as a regular expression. The <b>-w</b> (match as a word) and <b>-x</b>
261: (match whole line) options can be used with <b>-F</b>. They apply to each of the
262: fixed strings. A line is selected if any of the fixed strings are found in it
263: (subject to <b>-w</b> or <b>-x</b>, if present).
264: </P>
265: <P>
266: <b>-f</b> <i>filename</i>, <b>--file=</b><i>filename</i>
267: Read a number of patterns from the file, one per line, and match them against
268: each line of input. A data line is output if any of the patterns match it. The
269: filename can be given as "-" to refer to the standard input. When <b>-f</b> is
270: used, patterns specified on the command line using <b>-e</b> may also be
271: present; they are tested before the file's patterns. However, no other pattern
272: is taken from the command line; all arguments are treated as file names. There
273: is an overall maximum of 100 patterns. Trailing white space is removed from
274: each line, and blank lines are ignored. An empty file contains no patterns and
275: therefore matches nothing. See also the comments about multiple patterns versus
276: a single pattern with alternatives in the description of <b>-e</b> above.
277: </P>
278: <P>
279: <b>--file-offsets</b>
280: Instead of showing lines or parts of lines that match, show each match as an
281: offset from the start of the file and a length, separated by a comma. In this
282: mode, no context is shown. That is, the <b>-A</b>, <b>-B</b>, and <b>-C</b>
283: options are ignored. If there is more than one match in a line, each of them is
284: shown separately. This option is mutually exclusive with <b>--line-offsets</b>
285: and <b>--only-matching</b>.
286: </P>
287: <P>
288: <b>-H</b>, <b>--with-filename</b>
289: Force the inclusion of the filename at the start of output lines when searching
290: a single file. By default, the filename is not shown in this case. For matching
291: lines, the filename is followed by a colon; for context lines, a hyphen
292: separator is used. If a line number is also being output, it follows the file
293: name.
294: </P>
295: <P>
296: <b>-h</b>, <b>--no-filename</b>
297: Suppress the output filenames when searching multiple files. By default,
298: filenames are shown when multiple files are searched. For matching lines, the
299: filename is followed by a colon; for context lines, a hyphen separator is used.
300: If a line number is also being output, it follows the file name.
301: </P>
302: <P>
303: <b>--help</b>
304: Output a help message, giving brief details of the command options and file
305: type support, and then exit.
306: </P>
307: <P>
308: <b>-i</b>, <b>--ignore-case</b>
309: Ignore upper/lower case distinctions during comparisons.
310: </P>
311: <P>
312: <b>--include</b>=<i>pattern</i>
313: When <b>pcregrep</b> is searching the files in a directory as a consequence of
314: the <b>-r</b> (recursive search) option, only those regular files whose names
315: match the pattern are included. Subdirectories are always included and searched
316: recursively, subject to the \fP--include-dir\fP and <b>--exclude-dir</b>
317: options. The pattern is a PCRE regular expression, and is matched against the
318: final component of the file name (not the entire path). If a file name matches
319: both <b>--include</b> and <b>--exclude</b>, it is excluded. There is no short
320: form for this option.
321: </P>
322: <P>
323: <b>--include-dir</b>=<i>pattern</i>
324: When <b>pcregrep</b> is searching the contents of a directory as a consequence
325: of the <b>-r</b> (recursive search) option, only those subdirectories whose
326: names match the pattern are included. (Note that the <b>--include</b> option
327: does not affect subdirectories.) The pattern is a PCRE regular expression, and
328: is matched against the final component of the name (not the entire path). If a
329: subdirectory name matches both <b>--include-dir</b> and <b>--exclude-dir</b>, it
330: is excluded. There is no short form for this option.
331: </P>
332: <P>
333: <b>-L</b>, <b>--files-without-match</b>
334: Instead of outputting lines from the files, just output the names of the files
335: that do not contain any lines that would have been output. Each file name is
336: output once, on a separate line.
337: </P>
338: <P>
339: <b>-l</b>, <b>--files-with-matches</b>
340: Instead of outputting lines from the files, just output the names of the files
341: containing lines that would have been output. Each file name is output
342: once, on a separate line. Searching normally stops as soon as a matching line
343: is found in a file. However, if the <b>-c</b> (count) option is also used,
344: matching continues in order to obtain the correct count, and those files that
345: have at least one match are listed along with their counts. Using this option
346: with <b>-c</b> is a way of suppressing the listing of files with no matches.
347: </P>
348: <P>
349: <b>--label</b>=<i>name</i>
350: This option supplies a name to be used for the standard input when file names
351: are being output. If not supplied, "(standard input)" is used. There is no
352: short form for this option.
353: </P>
354: <P>
355: <b>--line-buffered</b>
356: When this option is given, input is read and processed line by line, and the
357: output is flushed after each write. By default, input is read in large chunks,
358: unless <b>pcregrep</b> can determine that it is reading from a terminal (which
359: is currently possible only in Unix environments). Output to terminal is
360: normally automatically flushed by the operating system. This option can be
361: useful when the input or output is attached to a pipe and you do not want
362: <b>pcregrep</b> to buffer up large amounts of data. However, its use will affect
363: performance, and the <b>-M</b> (multiline) option ceases to work.
364: </P>
365: <P>
366: <b>--line-offsets</b>
367: Instead of showing lines or parts of lines that match, show each match as a
368: line number, the offset from the start of the line, and a length. The line
369: number is terminated by a colon (as usual; see the <b>-n</b> option), and the
370: offset and length are separated by a comma. In this mode, no context is shown.
371: That is, the <b>-A</b>, <b>-B</b>, and <b>-C</b> options are ignored. If there is
372: more than one match in a line, each of them is shown separately. This option is
373: mutually exclusive with <b>--file-offsets</b> and <b>--only-matching</b>.
374: </P>
375: <P>
376: <b>--locale</b>=<i>locale-name</i>
377: This option specifies a locale to be used for pattern matching. It overrides
378: the value in the <b>LC_ALL</b> or <b>LC_CTYPE</b> environment variables. If no
379: locale is specified, the PCRE library's default (usually the "C" locale) is
380: used. There is no short form for this option.
381: </P>
382: <P>
383: <b>--match-limit</b>=<i>number</i>
384: Processing some regular expression patterns can require a very large amount of
385: memory, leading in some cases to a program crash if not enough is available.
386: Other patterns may take a very long time to search for all possible matching
387: strings. The <b>pcre_exec()</b> function that is called by <b>pcregrep</b> to do
388: the matching has two parameters that can limit the resources that it uses.
389: <br>
390: <br>
391: The <b>--match-limit</b> option provides a means of limiting resource usage
392: when processing patterns that are not going to match, but which have a very
393: large number of possibilities in their search trees. The classic example is a
394: pattern that uses nested unlimited repeats. Internally, PCRE uses a function
395: called <b>match()</b> which it calls repeatedly (sometimes recursively). The
396: limit set by <b>--match-limit</b> is imposed on the number of times this
397: function is called during a match, which has the effect of limiting the amount
398: of backtracking that can take place.
399: <br>
400: <br>
401: The <b>--recursion-limit</b> option is similar to <b>--match-limit</b>, but
402: instead of limiting the total number of times that <b>match()</b> is called, it
403: limits the depth of recursive calls, which in turn limits the amount of memory
404: that can be used. The recursion depth is a smaller number than the total number
405: of calls, because not all calls to <b>match()</b> are recursive. This limit is
406: of use only if it is set smaller than <b>--match-limit</b>.
407: <br>
408: <br>
409: There are no short forms for these options. The default settings are specified
410: when the PCRE library is compiled, with the default default being 10 million.
411: </P>
412: <P>
413: <b>-M</b>, <b>--multiline</b>
414: Allow patterns to match more than one line. When this option is given, patterns
415: may usefully contain literal newline characters and internal occurrences of ^
416: and $ characters. The output for a successful match may consist of more than
417: one line, the last of which is the one in which the match ended. If the matched
418: string ends with a newline sequence the output ends at the end of that line.
419: <br>
420: <br>
421: When this option is set, the PCRE library is called in "multiline" mode.
422: There is a limit to the number of lines that can be matched, imposed by the way
423: that <b>pcregrep</b> buffers the input file as it scans it. However,
424: <b>pcregrep</b> ensures that at least 8K characters or the rest of the document
425: (whichever is the shorter) are available for forward matching, and similarly
426: the previous 8K characters (or all the previous characters, if fewer than 8K)
427: are guaranteed to be available for lookbehind assertions. This option does not
428: work when input is read line by line (see \fP--line-buffered\fP.)
429: </P>
430: <P>
431: <b>-N</b> <i>newline-type</i>, <b>--newline</b>=<i>newline-type</i>
432: The PCRE library supports five different conventions for indicating
433: the ends of lines. They are the single-character sequences CR (carriage return)
434: and LF (linefeed), the two-character sequence CRLF, an "anycrlf" convention,
435: which recognizes any of the preceding three types, and an "any" convention, in
436: which any Unicode line ending sequence is assumed to end a line. The Unicode
437: sequences are the three just mentioned, plus VT (vertical tab, U+000B), FF
438: (form feed, U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and
439: PS (paragraph separator, U+2029).
440: <br>
441: <br>
442: When the PCRE library is built, a default line-ending sequence is specified.
443: This is normally the standard sequence for the operating system. Unless
444: otherwise specified by this option, <b>pcregrep</b> uses the library's default.
445: The possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This
446: makes it possible to use <b>pcregrep</b> on files that have come from other
447: environments without having to modify their line endings. If the data that is
448: being scanned does not agree with the convention set by this option,
449: <b>pcregrep</b> may behave in strange ways.
450: </P>
451: <P>
452: <b>-n</b>, <b>--line-number</b>
453: Precede each output line by its line number in the file, followed by a colon
454: for matching lines or a hyphen for context lines. If the filename is also being
455: output, it precedes the line number. This option is forced if
456: <b>--line-offsets</b> is used.
457: </P>
458: <P>
459: <b>--no-jit</b>
460: If the PCRE library is built with support for just-in-time compiling (which
461: speeds up matching), <b>pcregrep</b> automatically makes use of this, unless it
462: was explicitly disabled at build time. This option can be used to disable the
463: use of JIT at run time. It is provided for testing and working round problems.
464: It should never be needed in normal use.
465: </P>
466: <P>
467: <b>-o</b>, <b>--only-matching</b>
468: Show only the part of the line that matched a pattern instead of the whole
469: line. In this mode, no context is shown. That is, the <b>-A</b>, <b>-B</b>, and
470: <b>-C</b> options are ignored. If there is more than one match in a line, each
471: of them is shown separately. If <b>-o</b> is combined with <b>-v</b> (invert the
472: sense of the match to find non-matching lines), no output is generated, but the
473: return code is set appropriately. If the matched portion of the line is empty,
474: nothing is output unless the file name or line number are being printed, in
475: which case they are shown on an otherwise empty line. This option is mutually
476: exclusive with <b>--file-offsets</b> and <b>--line-offsets</b>.
477: </P>
478: <P>
479: <b>-o</b><i>number</i>, <b>--only-matching</b>=<i>number</i>
480: Show only the part of the line that matched the capturing parentheses of the
481: given number. Up to 32 capturing parentheses are supported. Because these
482: options can be given without an argument (see above), if an argument is
483: present, it must be given in the same shell item, for example, -o3 or
484: --only-matching=2. The comments given for the non-argument case above also
485: apply to this case. If the specified capturing parentheses do not exist in the
486: pattern, or were not set in the match, nothing is output unless the file name
487: or line number are being printed.
488: </P>
489: <P>
490: <b>-q</b>, <b>--quiet</b>
491: Work quietly, that is, display nothing except error messages. The exit
492: status indicates whether or not any matches were found.
493: </P>
494: <P>
495: <b>-r</b>, <b>--recursive</b>
496: If any given path is a directory, recursively scan the files it contains,
497: taking note of any <b>--include</b> and <b>--exclude</b> settings. By default, a
498: directory is read as a normal file; in some operating systems this gives an
499: immediate end-of-file. This option is a shorthand for setting the <b>-d</b>
500: option to "recurse".
501: </P>
502: <P>
503: <b>--recursion-limit</b>=<i>number</i>
504: See <b>--match-limit</b> above.
505: </P>
506: <P>
507: <b>-s</b>, <b>--no-messages</b>
508: Suppress error messages about non-existent or unreadable files. Such files are
509: quietly skipped. However, the return code is still 2, even if matches were
510: found in other files.
511: </P>
512: <P>
513: <b>-u</b>, <b>--utf-8</b>
514: Operate in UTF-8 mode. This option is available only if PCRE has been compiled
515: with UTF-8 support. Both patterns and subject lines must be valid strings of
516: UTF-8 characters.
517: </P>
518: <P>
519: <b>-V</b>, <b>--version</b>
520: Write the version numbers of <b>pcregrep</b> and the PCRE library that is being
521: used to the standard error stream.
522: </P>
523: <P>
524: <b>-v</b>, <b>--invert-match</b>
525: Invert the sense of the match, so that lines which do <i>not</i> match any of
526: the patterns are the ones that are found.
527: </P>
528: <P>
529: <b>-w</b>, <b>--word-regex</b>, <b>--word-regexp</b>
530: Force the patterns to match only whole words. This is equivalent to having \b
531: at the start and end of the pattern.
532: </P>
533: <P>
534: <b>-x</b>, <b>--line-regex</b>, <b>--line-regexp</b>
535: Force the patterns to be anchored (each must start matching at the beginning of
536: a line) and in addition, require them to match entire lines. This is
537: equivalent to having ^ and $ characters at the start and end of each
538: alternative branch in every pattern.
539: </P>
540: <br><a name="SEC5" href="#TOC1">ENVIRONMENT VARIABLES</a><br>
541: <P>
542: The environment variables <b>LC_ALL</b> and <b>LC_CTYPE</b> are examined, in that
543: order, for a locale. The first one that is set is used. This can be overridden
544: by the <b>--locale</b> option. If no locale is set, the PCRE library's default
545: (usually the "C" locale) is used.
546: </P>
547: <br><a name="SEC6" href="#TOC1">NEWLINES</a><br>
548: <P>
549: The <b>-N</b> (<b>--newline</b>) option allows <b>pcregrep</b> to scan files with
550: different newline conventions from the default. However, the setting of this
551: option does not affect the way in which <b>pcregrep</b> writes information to
552: the standard error and output streams. It uses the string "\n" in C
553: <b>printf()</b> calls to indicate newlines, relying on the C I/O library to
554: convert this to an appropriate sequence if the output is sent to a file.
555: </P>
556: <br><a name="SEC7" href="#TOC1">OPTIONS COMPATIBILITY</a><br>
557: <P>
558: Many of the short and long forms of <b>pcregrep</b>'s options are the same
559: as in the GNU <b>grep</b> program (version 2.5.4). Any long option of the form
560: <b>--xxx-regexp</b> (GNU terminology) is also available as <b>--xxx-regex</b>
561: (PCRE terminology). However, the <b>--file-offsets</b>, <b>--include-dir</b>,
562: <b>--line-offsets</b>, <b>--locale</b>, <b>--match-limit</b>, <b>-M</b>,
563: <b>--multiline</b>, <b>-N</b>, <b>--newline</b>, <b>--recursion-limit</b>,
564: <b>-u</b>, and <b>--utf-8</b> options are specific to <b>pcregrep</b>, as is the
565: use of the <b>--only-matching</b> option with a capturing parentheses number.
566: </P>
567: <P>
568: Although most of the common options work the same way, a few are different in
569: <b>pcregrep</b>. For example, the <b>--include</b> option's argument is a glob
570: for GNU <b>grep</b>, but a regular expression for <b>pcregrep</b>. If both the
571: <b>-c</b> and <b>-l</b> options are given, GNU grep lists only file names,
572: without counts, but <b>pcregrep</b> gives the counts.
573: </P>
574: <br><a name="SEC8" href="#TOC1">OPTIONS WITH DATA</a><br>
575: <P>
576: There are four different ways in which an option with data can be specified.
577: If a short form option is used, the data may follow immediately, or (with one
578: exception) in the next command line item. For example:
579: <pre>
580: -f/some/file
581: -f /some/file
582: </pre>
583: The exception is the <b>-o</b> option, which may appear with or without data.
584: Because of this, if data is present, it must follow immediately in the same
585: item, for example -o3.
586: </P>
587: <P>
588: If a long form option is used, the data may appear in the same command line
589: item, separated by an equals character, or (with two exceptions) it may appear
590: in the next command line item. For example:
591: <pre>
592: --file=/some/file
593: --file /some/file
594: </pre>
595: Note, however, that if you want to supply a file name beginning with ~ as data
596: in a shell command, and have the shell expand ~ to a home directory, you must
597: separate the file name from the option, because the shell does not treat ~
598: specially unless it is at the start of an item.
599: </P>
600: <P>
601: The exceptions to the above are the <b>--colour</b> (or <b>--color</b>) and
602: <b>--only-matching</b> options, for which the data is optional. If one of these
603: options does have data, it must be given in the first form, using an equals
604: character. Otherwise <b>pcregrep</b> will assume that it has no data.
605: </P>
606: <br><a name="SEC9" href="#TOC1">MATCHING ERRORS</a><br>
607: <P>
608: It is possible to supply a regular expression that takes a very long time to
609: fail to match certain lines. Such patterns normally involve nested indefinite
610: repeats, for example: (a+)*\d when matched against a line of a's with no final
611: digit. The PCRE matching function has a resource limit that causes it to abort
612: in these circumstances. If this happens, <b>pcregrep</b> outputs an error
613: message and the line that caused the problem to the standard error stream. If
614: there are more than 20 such errors, <b>pcregrep</b> gives up.
615: </P>
616: <P>
617: The <b>--match-limit</b> option of <b>pcregrep</b> can be used to set the overall
618: resource limit; there is a second option called <b>--recursion-limit</b> that
619: sets a limit on the amount of memory (usually stack) that is used (see the
620: discussion of these options above).
621: </P>
622: <br><a name="SEC10" href="#TOC1">DIAGNOSTICS</a><br>
623: <P>
624: Exit status is 0 if any matches were found, 1 if no matches were found, and 2
625: for syntax errors, overlong lines, non-existent or inaccessible files (even if
626: matches were found in other files) or too many matching errors. Using the
627: <b>-s</b> option to suppress error messages about inaccessible files does not
628: affect the return code.
629: </P>
630: <br><a name="SEC11" href="#TOC1">SEE ALSO</a><br>
631: <P>
632: <b>pcrepattern</b>(3), <b>pcretest</b>(1).
633: </P>
634: <br><a name="SEC12" href="#TOC1">AUTHOR</a><br>
635: <P>
636: Philip Hazel
637: <br>
638: University Computing Service
639: <br>
640: Cambridge CB2 3QH, England.
641: <br>
642: </P>
643: <br><a name="SEC13" href="#TOC1">REVISION</a><br>
644: <P>
645: Last updated: 06 September 2011
646: <br>
647: Copyright © 1997-2011 University of Cambridge.
648: <br>
649: <p>
650: Return to the <a href="index.html">PCRE index page</a>.
651: </p>
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to pcregrep.html CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / pcre / doc / html