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31 .\" @(#)grep.1 8.3 (Berkeley) 4/18/94
37 .Nm grep , egrep , fgrep ,
38 .Nm zgrep , zegrep , zfgrep
39 .Nd file pattern searcher
43 .Op Fl abcdDEFGHhIiJLlmnOopqRSsUVvwxZ
49 .Op Fl Fl binary-files Ns = Ns Ar value
50 .Op Fl Fl color Ns Op = Ns Ar when
51 .Op Fl Fl colour Ns Op = Ns Ar when
52 .Op Fl Fl context Ns Op = Ns Ar num
54 .Op Fl Fl line-buffered
62 utility searches any given input files,
63 selecting lines that match one or more patterns.
64 By default, a pattern matches an input line if the regular expression
65 (RE) in the pattern matches the input line
66 without its trailing newline.
67 An empty expression matches every line.
68 Each input line that matches at least one of the patterns is written
69 to the standard output.
72 is used for simple patterns and
73 basic regular expressions
76 can handle extended regular expressions
80 for more information on regular expressions.
86 but can only handle fixed patterns
87 (i.e. it does not interpret regular expressions).
88 Patterns may consist of one or more lines,
89 allowing any of the pattern lines to match a portion of the input.
100 respectively, but accept input files compressed with the
104 compression utilities.
106 The following options are available:
107 .Bl -tag -width indent
108 .It Fl A Ar num , Fl Fl after-context Ns = Ns Ar num
111 lines of trailing context after each match.
117 .It Fl a , Fl Fl text
118 Treat all files as ASCII text.
122 .Dq Binary file ... matches
123 if files contain binary characters.
124 Use of this option forces
126 to output lines matching the specified pattern.
127 .It Fl B Ar num , Fl Fl before-context Ns = Ns Ar num
130 lines of leading context before each match.
136 .It Fl b , Fl Fl byte-offset
137 The offset in bytes of a matched pattern is
138 displayed in front of the respective matched line.
139 .It Fl C Ns Op Ar num , Fl Fl context Ns = Ns Ar num
142 lines of leading and trailing context surrounding each match.
143 The default is 2 and is equivalent to
149 no whitespace may be given between the option and its argument.
150 .It Fl c , Fl Fl count
151 Only a count of selected lines is written to standard output.
152 .It Fl Fl colour Ns = Ns Op Ar when , Fl Fl color Ns = Ns Op Ar when
153 Mark up the matching text with the expression stored in
155 environment variable.
156 The possible values of when can be `never', `always' or `auto'.
157 .It Fl D Ar action , Fl Fl devices Ns = Ns Ar action
158 Specify the demanded action for devices, FIFOs and sockets.
159 The default action is `read', which means, that they are read
160 as if they were normal files.
161 If the action is set to `skip', devices will be silently skipped.
162 .It Fl d Ar action , Fl Fl directories Ns = Ns Ar action
163 Specify the demanded action for directories.
164 It is `read' by default, which means that the directories
165 are read in the same manner as normal files.
166 Other possible values are `skip' to silently ignore the
167 directories, and `recurse' to read them recursively, which
168 has the same effect as the
173 .It Fl E , Fl Fl extended-regexp
176 as an extended regular expression
181 .It Fl e Ar pattern , Fl Fl regexp Ns = Ns Ar pattern
182 Specify a pattern used during the search of the input:
183 an input line is selected if it matches any of the specified patterns.
184 This option is most useful when multiple
186 options are used to specify multiple patterns,
187 or when a pattern begins with a dash
190 If specified, it excludes files matching the given
191 filename pattern from the search.
194 patterns take priority over
198 pattern is specified, all files are searched that are
200 Patterns are matched to the full path specified,
201 not only to the filename component.
202 .It Fl Fl exclude-dir
205 is specified, it excludes directories matching the
206 given filename pattern from the search.
209 patterns take priority over
213 pattern is specified, all directories are searched that are
215 .It Fl F , Fl Fl fixed-strings
218 as a set of fixed strings
223 .It Fl f Ar file , Fl Fl file Ns = Ns Ar file
224 Read one or more newline separated patterns from
226 Empty pattern lines match every input line.
227 Newlines are not considered part of a pattern.
230 is empty, nothing is matched.
231 .It Fl G , Fl Fl basic-regexp
234 as a basic regular expression
237 to behave as traditional
240 Always print filename headers with output lines.
241 .It Fl h , Fl Fl no-filename
242 Never print filename headers
246 Print a brief help message.
249 This option is equivalent to
250 .Fl Fl binary-file Ns = Ns Ar without-match
252 .It Fl i , Fl Fl ignore-case
253 Perform case insensitive matching.
258 If specified, only files matching the
259 given filename pattern are searched.
262 patterns take priority over
265 Patterns are matched to the full path specified,
266 not only to the filename component.
267 .It Fl Fl include-dir
270 is specified, only directories matching the
271 given filename pattern are searched.
274 patterns take priority over
277 .It Fl J, Fl Fl bz2decompress
280 compressed file before looking for the text.
281 .It Fl L , Fl Fl files-without-match
282 Only the names of files not containing selected lines are written to
284 Pathnames are listed once per file searched.
285 If the standard input is searched, the string
288 .It Fl l , Fl Fl files-with-matches
289 Only the names of files containing selected lines are written to
292 will only search a file until a match has been found,
293 making searches potentially less expensive.
294 Pathnames are listed once per file searched.
295 If the standard input is searched, the string
303 to read input, which can result in better performance under some
304 circumstances but can cause undefined behaviour.
305 .It Fl m Ar num, Fl Fl max-count Ns = Ns Ar num
306 Stop reading the file after
309 .It Fl n , Fl Fl line-number
310 Each output line is preceded by its relative line number in the file,
312 The line number counter is reset for each file processed.
313 This option is ignored if
322 Prints a zero-byte after the file name.
326 is specified, follow symbolic links only if they were explicitly listed
328 The default is not to follow symbolic links.
329 .It Fl o, Fl Fl only-matching
330 Prints only the matching part of the lines.
334 is specified, no symbolic links are followed.
336 .It Fl q , Fl Fl quiet , Fl Fl silent
338 suppress normal output.
340 will only search a file until a match has been found,
341 making searches potentially less expensive.
342 .It Fl R , Fl r , Fl Fl recursive
343 Recursively search subdirectories listed.
347 is specified, all symbolic links are followed.
348 The default is not to follow symbolic links.
349 .It Fl s , Fl Fl no-messages
351 Nonexistent and unreadable files are ignored
352 (i.e. their error messages are suppressed).
353 .It Fl U , Fl Fl binary
354 Search binary files, but do not attempt to print them.
356 This option has no effect and is provided only for compatibility with GNU grep.
357 .It Fl V , Fl Fl version
358 Display version information and exit.
359 .It Fl v , Fl Fl invert-match
360 Selected lines are those
362 matching any of the specified patterns.
363 .It Fl w , Fl Fl word-regexp
364 The expression is searched for as a word (as if surrounded by
370 .It Fl x , Fl Fl line-regexp
371 Only input lines selected against an entire fixed string or regular
372 expression are considered to be matching lines.
377 .It Fl Z , Fl z , Fl Fl decompress
382 .It Fl Fl binary-files Ns = Ns Ar value
383 Controls searching and printing of binary files.
386 the default: search binary files but do not print them;
388 do not search binary files;
391 treat all files as text.
393 .It Fl Fl context Op = Ar num
397 lines of leading and trailing context.
399 .It Fl Fl line-buffered
400 Force output to be line buffered.
401 By default, output is line buffered when standard output is a terminal
402 and block buffered otherwise.
405 If no file arguments are specified, the standard input is used.
409 utility exits with one of the following values:
411 .Bl -tag -width flag -compact
413 One or more lines were selected.
415 No lines were selected.
420 To find all occurrences of the word
424 .Dl $ grep 'patricia' myfile
426 To find all occurrences of the pattern
428 at the beginning of a line:
430 .Dl $ grep '^\e.Pp' myfile
432 The apostrophes ensure the entire expression is evaluated by
434 instead of by the user's shell.
437 matches the null string at the beginning of a line,
442 which would otherwise match any character.
444 To find all lines in a file which do not contain the words
449 .Dl $ grep -v -e 'foo' -e 'bar' myfile
451 A simple example of an extended regular expression:
453 .Dl $ egrep '19|20|25' calendar
457 looking for either 19, 20, or 25.
467 utility is compliant with the
472 .Op Fl AaBbCDdGHhIJLmoPRSUVwZ
473 are extensions to that specification, and the behaviour of the
475 flag when used with an empty pattern file is left undefined.
477 All long options are provided for compatibility with
478 GNU versions of this utility.
480 Historic versions of the
482 utility also supported the flags
484 This implementation supports those options;
485 however, their use is strongly discouraged.
489 command first appeared in