/usr/man2/cat.1/pcregrep.1.Z
NAME
pcregrep - a grep with Perl-compatible regular expressions.
SYNOPSIS
pcregrep [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 pcrepattern for a full description of syntax and semantics
of the regular expressions that PCRE supports.
A pattern must be specified on the command line unless the -f option is
used (see below).
If no files are specified, pcregrep reads the standard input. The stan-
dard 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 the pattern is copied to the stan-
dard output, and if there is more than one file, the file name is
printed before each line of output. However, there are options that can
change how pcregrep behaves. In particular, the -M option makes it pos-
sible to search for patterns that span line boundaries.
Patterns are limited to 8K or BUFSIZ characters, whichever is the
greater. BUFSIZ is defined in <stdio.h>.
OPTIONS
-- This terminate the list of options. It is useful if the next
item on the command line starts with a hyphen, but is not an
option.
-A number Print number lines of context after each matching line. If
file names and/or line numbers are being printed, a hyphen
separator is used instead of a colon for the context lines. A
line containing "--" is printed 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 avail-
able for context printing.
-B number Print number lines of context before each matching line. If
file names and/or line numbers are being printed, a hyphen
separator is used instead of a colon for the context lines. A
line containing "--" is printed 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 avail-
able for context printing.
-C number Print 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 Do not print individual lines; instead just print a count of
the number of lines that would otherwise have been printed.
If several files are given, a count is printed for each of
them.
--exclude=pattern
When pcregrep is searching the files in a directory as a con-
sequence of the -r (recursive search) option, any files whose
names match the pattern are excluded. The pattern is a PCRE
regular expression. If a file name matches both --include and
--exclude, it is excluded. There is no short form for this
option.
-ffilename
Read a number of patterns from the file, one per line, and
match all of them against each line of input. A line is out-
put if any of the patterns match it. When -f is used, no
pattern is taken from the command line; all arguments are
treated as file names. There is a maximum of 100 patterns.
Trailing white space is removed, and blank lines are ignored.
An empty file contains no patterns and therefore matches
nothing.
-h Suppress printing of filenames when searching multiple files.
-i Ignore upper/lower case distinctions during comparisons.
--include=pattern
When pcregrep is searching the files in a directory as a con-
sequence of the -r (recursive search) option, only files
whose names match the pattern are included. The pattern is a
PCRE regular expression. If a file name matches both
--include and --exclude, it is excluded. There is no short
form for this option.
-L Instead of printing lines from the files, just print the
names of the files that do not contain any lines that would
have been printed. Each file name is printed once, on a sepa-
rate line.
-l Instead of printing lines from the files, just print the
names of the files containing lines that would have been
printed. Each file name is printed once, on a separate line.
--label=name
This option supplies a name to be used for the standard input
when file names are being printed. If not supplied, "(stan-
dard input)" is used. There is no short form for this option.
-M Allow patterns to match more than one line. When this option
is given, patterns may usefully contain literal newline char-
acters and internal occurrences of ^ and $ characters. The
output for any one match may consist of more than one line.
When this option is set, the PCRE library is called in "mul-
tiline" 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 simi-
larly the previous 8K characters (or all the previous charac-
ters, if fewer than 8K) are guaranteed to be available for
lookbehind assertions.
-n Precede each line by its line number in the file.
-q Work quietly, that is, display nothing except error messages.
The exit status indicates whether or not any matches were
found.
-r If any given path is a directory, recursively scan the files
it contains, taking note of any --include and --exclude set-
tings. Without -r a directory is scanned as a normal file.
-s 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 Operate in UTF-8 mode. This option is available only if PCRE
has been compiled with UTF-8 support. Both the pattern and
each subject line must be valid strings of UTF-8 characters.
-V Write the version numbers of pcregrep and the PCRE library
that is being used to the standard error stream.
-v Invert the sense of the match, so that lines which do not
match the pattern are the ones that are found.
-w Force the pattern to match only whole words. This is equiva-
lent to having \b at the start and end of the pattern.
-x Force the pattern to be anchored (it must start matching at
the beginning of the line) and in addition, require it to
match the entire line. This is equivalent to having ^ and $
characters at the start and end of each alternative branch in
the regular expression.
LONG OPTIONS
Long forms of all the options are available, as in GNU grep. They are
shown in the following table:
-A --after-context
-B --before-context
-C --context
-c --count
--exclude (no short form)
-f --file
-h --no-filename
--help (no short form)
-i --ignore-case
--include (no short form)
-L --files-without-match
-l --files-with-matches
--label (no short form)
-n --line-number
-r --recursive
-q --quiet
-s --no-messages
-u --utf-8
-V --version
-v --invert-match
-x --line-regex
-x --line-regexp
OPTIONS WITH DATA
There are four different ways in which an option with data can be spec-
ified. If a short form option is used, the data may follow immedi-
ately, or in the next command line item. For example:
-f/some/file
-f /some/file
If a long form option is used, the data may appear in the same command
line item, separated by an = character, or it may appear in the next
command line item. For example:
--file=/some/file
--file /some/file
DIAGNOSTICS
Exit status is 0 if any matches were found, 1 if no matches were found,
and 2 for syntax errors and non-existent or inacessible files (even if
matches were found in other files). Using the -s option to suppress
error messages about inaccessble files does not affect the return code.
AUTHOR
Philip Hazel
University Computing Service
Cambridge CB2 3QG, England.
Last updated: 16 May 2005
Copyright (c) 1997-2005 University of Cambridge.
PCREGREP(1)
See also pgrep(1)
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