Provided by: pcregrep_8.39-12_amd64 bug

NAME

       pcregrep - a grep with Perl-compatible regular expressions.

SYNOPSIS

       pcregrep  [options]  [long options] [pattern] [path1 path2 ...]  zpcregrep [options] [long
       options] [pattern] [file1 file2 ...]

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 pcresyntax(3) for a quick-reference summary of
       pattern  syntax,  or  pcrepattern(3) for a full description of the syntax 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
       metacharacters.

       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
       particular, 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
       parameter 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
       following the match, so that further matches on the same line can be found. If  there  are
       multiple  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.

       zpcregrep is a wrapper script that allows pcregrep to work on gzip compressed files.

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
       appropriate 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
       identified 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
                 command  line  starts  with  a  hyphen but is not an option. This allows for the
                 processing 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
                 control 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
                 compatibility 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
                 patterns.  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
                 specified 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
                 system'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 contains 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
                 command  line  using  -e  may also be present; they are tested before the file's
                 patterns. 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
                 separator  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,
                 filenames  are  shown  when multiple files are searched. For matching lines, the
                 filename 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=without-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
                 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. 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
                 number of times; all the files are read.

       --include-dir=pattern
                 If any --include-dir patterns are  specified,  the  only  directories  that  are
                 processed  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
                 suppressing 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
                 currently  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-
                 offsets 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
                 specified, 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
                 processing  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
                 limiting 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
                 recognizes  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
                 otherwise  specified  by  this option, pcregrep uses the library's default.  The
                 possible values for this option are CR, LF, CRLF, ANYCRLF, or ANY. This makes it
                 possible  to  use  pcregrep to scan files that have come from other environments
                 without 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
                 operating 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
                 output, 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
                 separately. 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
                 appropriately. 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
                 equivalent to -o without a number. Because these options can be given without an
                 argument (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
                 parentheses  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
                 output 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
                 patterns 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
                 specified 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
       informational  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
       expression 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,
       separated  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: 03 April 2014
       Copyright (c) 1997-2014 University of Cambridge.