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PCREGREP(1)									      PCREGREP(1)

NAME
       pcregrep - a grep with Perl-compatible regular expressions.

SYNOPSIS
       pcregrep [options] [long options] [pattern] [path1 path2 ...]

DESCRIPTION

       pcregrep searches files for character patterns, in the same way as other grep commands do,
       but it uses the PCRE regular expression library to support patterns  that  are  compatible
       with  the regular expressions of Perl 5. See pcrepattern(3) for a full description of syn-
       tax and semantics of the regular expressions that PCRE supports.

       Patterns, whether supplied on the command line or in a separate file,  are  given  without
       delimiters. For example:

	 pcregrep Thursday /etc/motd

       If  you	attempt to use delimiters (for example, by surrounding a pattern with slashes, as
       is common in Perl scripts), they are interpreted as part of the	pattern.  Quotes  can  of
       course be used to delimit patterns on the command line because they are interpreted by the
       shell, and indeed quotes are required if a pattern contains white space or shell metachar-
       acters.

       The first argument that follows any option settings is treated as the single pattern to be
       matched when neither -e nor -f is present.  Conversely, when one or both of these  options
       are used to specify patterns, all arguments are treated as path names. At least one of -e,
       -f, or an argument pattern must be provided.

       If no files are specified, pcregrep reads the standard input. The standard input can  also
       be referenced by a name consisting of a single hyphen.  For example:

	 pcregrep some-pattern /file1 - /file3

       By  default,  each  line  that  matches a pattern is copied to the standard output, and if
       there is more than one file, the file name is output at the start of each  line,  followed
       by  a  colon. However, there are options that can change how pcregrep behaves. In particu-
       lar, the -M option makes it possible to search for patterns  that  span	line  boundaries.
       What defines a line boundary is controlled by the -N (--newline) option.

       The  amount  of	memory used for buffering files that are being scanned is controlled by a
       parameter that can be set by the --buffer-size option.  The default value for this parame-
       ter  is	specified  when pcregrep is built, with the default default being 20K. A block of
       memory three times this size is used (to allow for buffering "before" and "after"  lines).
       An error occurs if a line overflows the buffer.

       Patterns  can  be  no longer than 8K or BUFSIZ bytes, whichever is the greater.	BUFSIZ is
       defined in <stdio.h>. When there is more than one pattern (specified  by  the  use  of  -e
       and/or  -f),  each pattern is applied to each line in the order in which they are defined,
       except that all the -e patterns are tried before the -f patterns.

       By default, as soon as one pattern matches a line, no  further  patterns  are  considered.
       However, if --colour (or --color) is used to colour the matching substrings, or if --only-
       matching, --file-offsets, or --line-offsets is used to output only the part  of	the  line
       that  matched (either shown literally, or as an offset), scanning resumes immediately fol-
       lowing the match, so that further matches on the same line can be found. If there are mul-
       tiple  patterns, they are all tried on the remainder of the line, but patterns that follow
       the one that matched are not tried on the earlier part of the line.

       This behaviour means that the order in which multiple patterns are  specified  can  affect
       the  output when one of the above options is used. This is no longer the same behaviour as
       GNU grep, which now manages to display earlier matches for  later  patterns  (as  long  as
       there is no overlap).

       Patterns  that  can match an empty string are accepted, but empty string matches are never
       recognized. An example is the  pattern  "(super)?(man)?",  in  which  all  components  are
       optional. This pattern finds all occurrences of both "super" and "man"; the output differs
       from matching with "super|man" when only the matching substrings are being shown.

       If the LC_ALL or LC_CTYPE environment variable is set, pcregrep uses the value  to  set	a
       locale when calling the PCRE library.  The --locale option can be used to override this.

SUPPORT FOR COMPRESSED FILES

       It  is  possible  to  compile  pcregrep so that it uses libz or libbz2 to read files whose
       names end in .gz or .bz2, respectively. You can find out whether your binary  has  support
       for one or both of these file types by running it with the --help option. If the appropri-
       ate support is not present, files are treated as plain text. The standard input is  always
       so treated.

BINARY FILES

       By default, a file that contains a binary zero byte within the first 1024 bytes is identi-
       fied as a binary file, and is processed specially. (GNU grep also identifies binary  files
       in  this  manner.)  See	the  --binary-files option for a means of changing the way binary
       files are handled.

OPTIONS

       The order in which some of the options appear can affect the output. For example, both the
       -h  and -l options affect the printing of file names. Whichever comes later in the command
       line will be the one that takes effect. Similarly, except where noted below, if an  option
       is given twice, the later setting is used. Numerical values for options may be followed by
       K or M, to signify multiplication by 1024 or 1024*1024 respectively.

       --	 This terminates the list of options. It is useful if the next item on	the  com-
		 mand  line  starts  with a hyphen but is not an option. This allows for the pro-
		 cessing of patterns and filenames that start with hyphens.

       -A number, --after-context=number
		 Output number lines of context after each matching  line.  If	filenames  and/or
		 line numbers are being output, a hyphen separator is used instead of a colon for
		 the context lines. A line containing "--" is output between each group of lines,
		 unless  they  are  in	fact contiguous in the input file. The value of number is
		 expected to be relatively small. However, pcregrep guarantees to have up  to  8K
		 of following text available for context output.

       -a, --text
		 Treat binary files as text. This is equivalent to --binary-files=text.

       -B number, --before-context=number
		 Output  number  lines	of context before each matching line. If filenames and/or
		 line numbers are being output, a hyphen separator is used instead of a colon for
		 the context lines. A line containing "--" is output between each group of lines,
		 unless they are in fact contiguous in the input file. The  value  of  number  is
		 expected  to  be relatively small. However, pcregrep guarantees to have up to 8K
		 of preceding text available for context output.

       --binary-files=word
		 Specify how binary files are to be processed.	If  the  word  is  "binary"  (the
		 default),  pattern matching is performed on binary files, but the only output is
		 "Binary file <name> matches" when a match succeeds. If the word is "text", which
		 is equivalent to the -a or --text option, binary files are processed in the same
		 way as any other file. In this case, when a match succeeds, the  output  may  be
		 binary  garbage, which can have nasty effects if sent to a terminal. If the word
		 is "without-match", which is equivalent to the -I option, binary files  are  not
		 processed at all; they are assumed not to be of interest.

       --buffer-size=number
		 Set the parameter that controls how much memory is used for buffering files that
		 are being scanned.

       -C number, --context=number
		 Output number lines of context both before and after each matching  line.   This
		 is equivalent to setting both -A and -B to the same value.

       -c, --count
		 Do  not  output  individual lines from the files that are being scanned; instead
		 output the number of lines that would otherwise have been shown. If no lines are
		 selected,  the  number zero is output. If several files are are being scanned, a
		 count is output for each of them. However, if the --files-with-matches option is
		 also  used, only those files whose counts are greater than zero are listed. When
		 -c is used, the -A, -B, and -C options are ignored.

       --colour, --color
		 If this option is given without any data, it is equivalent  to  "--colour=auto".
		 If  data  is  required, it must be given in the same shell item, separated by an
		 equals sign.

       --colour=value, --color=value
		 This option specifies under what circumstances the parts of a line that  matched
		 a  pattern  should  be  coloured  in  the  output. By default, the output is not
		 coloured. The value (which is optional, see above) may be "never", "always",  or
		 "auto".  In  the  latter  case, colouring happens only if the standard output is
		 connected to a terminal. More resources are  used  when  colouring  is  enabled,
		 because pcregrep has to search for all possible matches in a line, not just one,
		 in order to colour them all.

		 The colour that is used can be specified by  setting  the  environment  variable
		 PCREGREP_COLOUR or PCREGREP_COLOR. The value of this variable should be a string
		 of two numbers, separated by a semicolon. They are copied directly into the con-
		 trol  string  for  setting colour on a terminal, so it is your responsibility to
		 ensure that they make sense. If neither of the environment variables is set, the
		 default is "1;31", which gives red.

       -D action, --devices=action
		 If an input path is not a regular file or a directory, "action" specifies how it
		 is to be processed. Valid values are "read" (the default)  or	"skip"	(silently
		 skip the path).

       -d action, --directories=action
		 If  an  input path is a directory, "action" specifies how it is to be processed.
		 Valid values are "read" (the default in non-Windows environments,  for  compati-
		 bility  with  GNU  grep),  "recurse"  (equivalent  to	the -r option), or "skip"
		 (silently skip the path, the default in Windows  environments).  In  the  "read"
		 case,	directories  are  read	as if they were ordinary files. In some operating
		 systems the effect of reading a directory like this is an immediate end-of-file;
		 in others it may provoke an error.

       -e pattern, --regex=pattern, --regexp=pattern
		 Specify a pattern to be matched. This option can be used multiple times in order
		 to specify several patterns. It can also be used as a way of specifying a single
		 pattern that starts with a hyphen. When -e is used, no argument pattern is taken
		 from the command line; all arguments are treated as  file  names.  There  is  no
		 limit	to  the number of patterns. They are applied to each line in the order in
		 which they are defined until one matches.

		 If -f is used with -e, the command line patterns are matched first, followed  by
		 the  patterns	from the file(s), independent of the order in which these options
		 are specified. Note that multiple use of -e is not the same as a single  pattern
		 with  alternatives. For example, X|Y finds the first character in a line that is
		 X or Y, whereas if the two patterns are given separately, with X first, pcregrep
		 finds	X  if it is present, even if it follows Y in the line. It finds Y only if
		 there is no X in the line. This matters only if you are using -o  or  --colo(u)r
		 to show the part(s) of the line that matched.

       --exclude=pattern
		 Files	(but  not  directories) whose names match the pattern are skipped without
		 being processed. This applies to all files, whether listed on the command  line,
		 obtained  from  --file-list,  or  by scanning a directory. The pattern is a PCRE
		 regular expression, and is matched against the final component of the file name,
		 not  the  entire  path. The -F, -w, and -x options do not apply to this pattern.
		 The option may be given any number of times in order to  specify  multiple  pat-
		 terns.  If a file name matches both an --include and an --exclude pattern, it is
		 excluded. There is no short form for this option.

       --exclude-from=filename
		 Treat each non-empty line of the file as the data for an --exclude option.  What
		 constitutes  a  newline when reading the file is the operating system's default.
		 The --newline option has no effect on this option. This option may be given more
		 than once in order to specify a number of files to read.

       --exclude-dir=pattern
		 Directories  whose  names match the pattern are skipped without being processed,
		 whatever the setting of the --recursive option. This applies to all directories,
		 whether  listed on the command line, obtained from --file-list, or by scanning a
		 parent directory. The pattern is a  PCRE  regular  expression,  and  is  matched
		 against  the final component of the directory name, not the entire path. The -F,
		 -w, and -x options do not apply to this pattern. The option  may  be  given  any
		 number  of  times  in	order  to  specify  more than one pattern. If a directory
		 matches both --include-dir and --exclude-dir, it is excluded. There is no  short
		 form for this option.

       -F, --fixed-strings
		 Interpret  each  data-matching  pattern as a list of fixed strings, separated by
		 newlines, instead of as a regular expression. What  constitutes  a  newline  for
		 this purpose is controlled by the --newline option. The -w (match as a word) and
		 -x (match whole line) options can be used with -F.  They apply to  each  of  the
		 fixed	strings.  A  line is selected if any of the fixed strings are found in it
		 (subject to -w or -x, if present). This option applies only to the patterns that
		 are  matched against the contents of files; it does not apply to patterns speci-
		 fied by any of the --include or --exclude options.

       -f filename, --file=filename
		 Read patterns from the file, one per line, and match them against each  line  of
		 input.  What  constitutes  a newline when reading the file is the operating sys-
		 tem's default. The --newline option has no effect on this option. Trailing white
		 space is removed from each line, and blank lines are ignored. An empty file con-
		 tains no patterns and therefore matches nothing. See  also  the  comments  about
		 multiple  patterns  versus a single pattern with alternatives in the description
		 of -e above.

		 If this option is given more than once, all the specified files are read. A data
		 line  is  output if any of the patterns match it. A filename can be given as "-"
		 to refer to the standard input. When -f is used, patterns specified on the  com-
		 mand  line  using -e may also be present; they are tested before the file's pat-
		 terns. However, no other pattern is taken from the command line;  all	arguments
		 are treated as the names of paths to be searched.

       --file-list=filename
		 Read  a  list	of files and/or directories that are to be scanned from the given
		 file, one per line. Trailing white space is removed from each	line,  and  blank
		 lines	are  ignored. These paths are processed before any that are listed on the
		 command line. The filename can be given as "-" to refer to the  standard  input.
		 If  --file  and  --file-list are both specified as "-", patterns are read first.
		 This is useful only when the standard input is a terminal,  from  which  further
		 lines	(the  list of files) can be read after an end-of-file indication. If this
		 option is given more than once, all the specified files are read.

       --file-offsets
		 Instead of showing lines or parts of lines that match, show  each  match  as  an
		 offset  from  the  start of the file and a length, separated by a comma. In this
		 mode, no context is shown. That is, the -A, -B, and -C options are  ignored.  If
		 there	is  more than one match in a line, each of them is shown separately. This
		 option is mutually exclusive with --line-offsets and --only-matching.

       -H, --with-filename
		 Force the inclusion of the filename at the start of output lines when	searching
		 a  single file. By default, the filename is not shown in this case. For matching
		 lines, the filename is followed by a colon; for context lines, a hyphen  separa-
		 tor is used. If a line number is also being output, it follows the file name.

       -h, --no-filename
		 Suppress  the	output filenames when searching multiple files. By default, file-
		 names are shown when multiple files are searched. For matching lines, the  file-
		 name  is followed by a colon; for context lines, a hyphen separator is used.  If
		 a line number is also being output, it follows the file name.

       --help	 Output a help message, giving brief details of the command options and file type
		 support, and then exit. Anything else on the command line is ignored.

       -I	 Treat binary files as never matching. This is equivalent to --binary-files=with-
		 out-match.

       -i, --ignore-case
		 Ignore upper/lower case distinctions during comparisons.

       --include=pattern
		 If any --include patterns are specified, the only files that are  processed  are
		 those	that  match  one of the patterns (and do not match an --exclude pattern).
		 This option does not affect directories, but it applies to  all  files,  whether
		 listed  on  the command line, obtained from --file-list, or by scanning a direc-
		 tory. The pattern is a PCRE regular expression, and is matched against the final
		 component  of	the file name, not the entire path. The -F, -w, and -x options do
		 not apply to this pattern. The option may be given any number	of  times.  If	a
		 file  name  matches  both an --include and an --exclude pattern, it is excluded.
		 There is no short form for this option.

       --include-from=filename
		 Treat each non-empty line of the file as the data for an --include option.  What
		 constitutes  a  newline  for this purpose is the operating system's default. The
		 --newline option has no effect on this option. This option may be given any num-
		 ber of times; all the files are read.

       --include-dir=pattern
		 If  any --include-dir patterns are specified, the only directories that are pro-
		 cessed are those that match one of the patterns (and do not match an  --exclude-
		 dir  pattern).  This  applies	to all directories, whether listed on the command
		 line, obtained from --file-list, or by scanning a parent directory. The  pattern
		 is  a PCRE regular expression, and is matched against the final component of the
		 directory name, not the entire path. The -F, -w, and -x options do not apply  to
		 this  pattern.  The  option  may  be  given  any number of times. If a directory
		 matches both --include-dir and --exclude-dir, it is excluded. There is no  short
		 form for this option.

       -L, --files-without-match
		 Instead  of  outputting lines from the files, just output the names of the files
		 that do not contain any lines that would have been output.  Each  file  name  is
		 output once, on a separate line.

       -l, --files-with-matches
		 Instead  of  outputting lines from the files, just output the names of the files
		 containing lines that would have been output. Each file name is output once,  on
		 a separate line. Searching normally stops as soon as a matching line is found in
		 a file. However, if the -c (count) option is also used,  matching  continues  in
		 order	to obtain the correct count, and those files that have at least one match
		 are listed along with their counts. Using this option with -c is a way  of  sup-
		 pressing the listing of files with no matches.

       --label=name
		 This  option  supplies  a name to be used for the standard input when file names
		 are being output. If not supplied, "(standard input)" is used. There is no short
		 form for this option.

       --line-buffered
		 When  this  option  is  given, input is read and processed line by line, and the
		 output is flushed after each write. By default, input is read in  large  chunks,
		 unless  pcregrep can determine that it is reading from a terminal (which is cur-
		 rently possible only in Unix-like environments). Output to terminal is  normally
		 automatically	flushed  by  the operating system. This option can be useful when
		 the input or output is attached to a pipe and you do not want pcregrep to buffer
		 up  large  amounts of data. However, its use will affect performance, and the -M
		 (multiline) option ceases to work.

       --line-offsets
		 Instead of showing lines or parts of lines that match, show each match as a line
		 number,  the offset from the start of the line, and a length. The line number is
		 terminated by a colon (as usual; see the -n option), and the offset  and  length
		 are  separated  by a comma. In this mode, no context is shown.  That is, the -A,
		 -B, and -C options are ignored. If there is more than one match in a line,  each
		 of  them is shown separately. This option is mutually exclusive with --file-off-
		 sets and --only-matching.

       --locale=locale-name
		 This option specifies a locale to be used for pattern matching. It overrides the
		 value	in  the  LC_ALL or LC_CTYPE environment variables. If no locale is speci-
		 fied, the PCRE library's default (usually the "C" locale) is used. There  is  no
		 short form for this option.

       --match-limit=number
		 Processing  some  regular expression patterns can require a very large amount of
		 memory, leading in some cases to a program crash if  not  enough  is  available.
		 Other	patterns  may  take  a very long time to search for all possible matching
		 strings. The pcre_exec() function that is called by pcregrep to do the  matching
		 has two parameters that can limit the resources that it uses.

		 The  --match-limit  option provides a means of limiting resource usage when pro-
		 cessing patterns that are not going to match, but which have a very large number
		 of  possibilities  in	their search trees. The classic example is a pattern that
		 uses nested unlimited repeats. Internally, PCRE uses a function  called  match()
		 which	it  calls  repeatedly  (sometimes recursively). The limit set by --match-
		 limit is imposed on the number of times this function is called during a  match,
		 which has the effect of limiting the amount of backtracking that can take place.

		 The  --recursion-limit option is similar to --match-limit, but instead of limit-
		 ing the total number of times that match() is called, it  limits  the	depth  of
		 recursive calls, which in turn limits the amount of memory that can be used. The
		 recursion depth is a smaller number than the total number of calls, because  not
		 all  calls  to  match()  are  recursive.  This limit is of use only if it is set
		 smaller than --match-limit.

		 There are no short forms for these options. The default settings  are	specified
		 when the PCRE library is compiled, with the default default being 10 million.

       -M, --multiline
		 Allow	patterns to match more than one line. When this option is given, patterns
		 may usefully contain literal newline characters and internal  occurrences  of	^
		 and $ characters. The output for a successful match may consist of more than one
		 line, the last of which is the one in which the  match  ended.  If  the  matched
		 string ends with a newline sequence the output ends at the end of that line.

		 When  this option is set, the PCRE library is called in "multiline" mode.  There
		 is a limit to the number of lines that can be matched, imposed by the	way  that
		 pcregrep  buffers  the input file as it scans it. However, pcregrep ensures that
		 at least 8K characters or the rest of the document (whichever	is  the  shorter)
		 are available for forward matching, and similarly the previous 8K characters (or
		 all the previous characters, if fewer than 8K) are guaranteed	to  be	available
		 for  lookbehind assertions. This option does not work when input is read line by
		 line (see --line-buffered.)

       -N newline-type, --newline=newline-type
		 The PCRE library supports five different conventions for indicating the ends  of
		 lines.  They  are  the  single-character  sequences  CR (carriage return) and LF
		 (linefeed), the two-character sequence CRLF, an "anycrlf" convention, which rec-
		 ognizes  any of the preceding three types, and an "any" convention, in which any
		 Unicode line ending sequence is assumed to end a line. The Unicode sequences are
		 the  three  just  mentioned,  plus  VT  (vertical  tab,  U+000B), FF (form feed,
		 U+000C), NEL (next line, U+0085), LS (line separator, U+2028), and PS (paragraph
		 separator, U+2029).

		 When  the  PCRE  library  is built, a default line-ending sequence is specified.
		 This is normally the standard sequence for the operating system.  Unless  other-
		 wise  specified by this option, pcregrep uses the library's default.  The possi-
		 ble values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This makes it pos-
		 sible to use pcregrep to scan files that have come from other environments with-
		 out having to modify their line endings. If the data that is being scanned  does
		 not agree with the convention set by this option, pcregrep may behave in strange
		 ways. Note that this option does  not	apply  to  files  specified  by  the  -f,
		 --exclude-from, or --include-from options, which are expected to use the operat-
		 ing system's standard newline sequence.

       -n, --line-number
		 Precede each output line by its line number in the file, followed by a colon for
		 matching lines or a hyphen for context lines. If the filename is also being out-
		 put, it precedes the line number. This option is  forced  if  --line-offsets  is
		 used.

       --no-jit  If  the  PCRE	library  is  built with support for just-in-time compiling (which
		 speeds up matching), pcregrep automatically makes use of  this,  unless  it  was
		 explicitly disabled at build time. This option can be used to disable the use of
		 JIT at run time. It is provided for testing  and  working  round  problems.   It
		 should never be needed in normal use.

       -o, --only-matching
		 Show only the part of the line that matched a pattern instead of the whole line.
		 In this mode, no context is shown. That is, the  -A,  -B,  and  -C  options  are
		 ignored.  If there is more than one match in a line, each of them is shown sepa-
		 rately. If -o is combined with -v (invert the sense of the match  to  find  non-
		 matching  lines),  no	output is generated, but the return code is set appropri-
		 ately. If the matched portion of the line is empty, nothing is output unless the
		 file  name  or line number are being printed, in which case they are shown on an
		 otherwise empty line. This option is mutually exclusive with --file-offsets  and
		 --line-offsets.

       -onumber, --only-matching=number
		 Show  only  the  part	of the line that matched the capturing parentheses of the
		 given number. Up to 32 capturing parentheses are supported, and -o0  is  equiva-
		 lent to -o without a number. Because these options can be given without an argu-
		 ment (see above), if an argument is present, it must be given in the same  shell
		 item,	for  example,  -o3  or --only-matching=2. The comments given for the non-
		 argument case above also apply to this case. If the specified	capturing  paren-
		 theses  do  not  exist  in the pattern, or were not set in the match, nothing is
		 output unless the file name or line number are being printed.

		 If this option is given multiple times, multiple substrings are output,  in  the
		 order	the  options  are  given.  For example, -o3 -o1 -o3 causes the substrings
		 matched by capturing parentheses 3 and 1 and then  3  again  to  be  output.  By
		 default, there is no separator (but see the next option).

       --om-separator=text
		 Specify  a  separating  string for multiple occurrences of -o. The default is an
		 empty string. Separating strings are never coloured.

       -q, --quiet
		 Work quietly, that is, display nothing except error messages.	The  exit  status
		 indicates whether or not any matches were found.

       -r, --recursive
		 If any given path is a directory, recursively scan the files it contains, taking
		 note of any --include and --exclude settings. By default, a directory is read as
		 a  normal  file;  in some operating systems this gives an immediate end-of-file.
		 This option is a shorthand for setting the -d option to "recurse".

       --recursion-limit=number
		 See --match-limit above.

       -s, --no-messages
		 Suppress error messages about non-existent or unreadable files. Such  files  are
		 quietly skipped. However, the return code is still 2, even if matches were found
		 in other files.

       -u, --utf-8
		 Operate in UTF-8 mode. This option is available only if PCRE has  been  compiled
		 with  UTF-8  support.	All  patterns  (including  those  for  any  --exclude and
		 --include options) and all subject lines that are scanned must be valid  strings
		 of UTF-8 characters.

       -V, --version
		 Write	the version numbers of pcregrep and the PCRE library to the standard out-
		 put and then exit. Anything else on the command line is ignored.

       -v, --invert-match
		 Invert the sense of the match, so that lines which do not match any of the  pat-
		 terns are the ones that are found.

       -w, --word-regex, --word-regexp
		 Force the patterns to match only whole words. This is equivalent to having \b at
		 the start and end of the pattern. This option applies only to the patterns  that
		 are  matched against the contents of files; it does not apply to patterns speci-
		 fied by any of the --include or --exclude options.

       -x, --line-regex, --line-regexp
		 Force the patterns to be anchored (each must start matching at the beginning  of
		 a  line) and in addition, require them to match entire lines. This is equivalent
		 to having ^ and $ characters at the start and end of each alternative branch  in
		 every pattern. This option applies only to the patterns that are matched against
		 the contents of files; it does not apply to patterns specified  by  any  of  the
		 --include or --exclude options.

ENVIRONMENT VARIABLES

       The  environment  variables LC_ALL and LC_CTYPE are examined, in that order, for a locale.
       The first one that is set is used. This can be overridden by the --locale  option.  If  no
       locale is set, the PCRE library's default (usually the "C" locale) is used.

NEWLINES

       The -N (--newline) option allows pcregrep to scan files with different newline conventions
       from the default. Any parts of the input files that are written to the standard output are
       copied  identically,  with whatever newline sequences they have in the input. However, the
       setting of this option does not affect the interpretation of files specified  by  the  -f,
       --exclude-from, or --include-from options, which are assumed to use the operating system's
       standard newline sequence, nor does it affect the way in which  pcregrep  writes  informa-
       tional  messages  to  the  standard error and output streams. For these it uses the string
       "\n" to indicate newlines, relying on the C I/O library to convert this to an  appropriate
       sequence.

OPTIONS COMPATIBILITY

       Many  of  the  short  and long forms of pcregrep's options are the same as in the GNU grep
       program. Any long option of the form --xxx-regexp (GNU terminology) is also  available  as
       --xxx-regex  (PCRE  terminology). However, the --file-list, --file-offsets, --include-dir,
       --line-offsets, --locale, --match-limit, -M, --multiline, -N,  --newline,  --om-separator,
       --recursion-limit,  -u, and --utf-8 options are specific to pcregrep, as is the use of the
       --only-matching option with a capturing parentheses number.

       Although most of the common options work the same way, a few are  different  in	pcregrep.
       For example, the --include option's argument is a glob for GNU grep, but a regular expres-
       sion for pcregrep. If both the -c and -l options are  given,  GNU  grep	lists  only  file
       names, without counts, but pcregrep gives the counts.

OPTIONS WITH DATA

       There  are  four different ways in which an option with data can be specified.  If a short
       form option is used, the data may follow immediately, or (with one exception) in the  next
       command line item. For example:

	 -f/some/file
	 -f /some/file

       The  exception  is the -o option, which may appear with or without data.  Because of this,
       if data is present, it must follow immediately in the same item, for example -o3.

       If a long form option is used, the data may appear in the same command  line  item,  sepa-
       rated  by  an equals character, or (with two exceptions) it may appear in the next command
       line item. For example:

	 --file=/some/file
	 --file /some/file

       Note, however, that if you want to supply a file name beginning with ~ as data in a  shell
       command,  and have the shell expand ~ to a home directory, you must separate the file name
       from the option, because the shell does not treat ~ specially unless it is at the start of
       an item.

       The exceptions to the above are the --colour (or --color) and --only-matching options, for
       which the data is optional. If one of these options does have data, it must  be	given  in
       the  first  form, using an equals character. Otherwise pcregrep will assume that it has no
       data.

MATCHING ERRORS

       It is possible to supply a regular expression that takes a very long time to fail to match
       certain	lines.	Such  patterns	normally  involve nested indefinite repeats, for example:
       (a+)*\d when matched against a line of a's with no final digit. The PCRE matching function
       has  a  resource  limit	that  causes it to abort in these circumstances. If this happens,
       pcregrep outputs an error message and the line that caused the  problem	to  the  standard
       error stream. If there are more than 20 such errors, pcregrep gives up.

       The  --match-limit option of pcregrep can be used to set the overall resource limit; there
       is a second option called --recursion-limit that sets a limit  on  the  amount  of  memory
       (usually stack) that is used (see the discussion of these options above).

DIAGNOSTICS

       Exit  status  is 0 if any matches were found, 1 if no matches were found, and 2 for syntax
       errors, overlong lines, non-existent or inaccessible files (even if matches were found  in
       other  files)  or too many matching errors. Using the -s option to suppress error messages
       about inaccessible files does not affect the return code.

SEE ALSO

       pcrepattern(3), pcresyntax(3), pcretest(1).

AUTHOR

       Philip Hazel
       University Computing Service
       Cambridge CB2 3QH, England.

REVISION

       Last updated: 13 September 2012
       Copyright (c) 1997-2012 University of Cambridge.

PCRE 8.32				13 September 2012			      PCREGREP(1)
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