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GREP(1)                 FreeBSD General Commands Manual                GREP(1)

NAME
     grep, egrep, fgrep, zgrep, zegrep, zfgrep - file pattern searcher

SYNOPSIS
     grep [-abcdDEFGHhIiJLlmnOopqRSsUVvwxZ] [-A num] [-B num] [-C[num]]
          [-e pattern] [-f file] [--binary-files=value] [--color[=when]]
          [--colour[=when]] [--context[=num]] [--label] [--line-buffered]
          [--null] [pattern] [file ...]

DESCRIPTION
     The grep utility searches any given input files, selecting lines that
     match one or more patterns.  By default, a pattern matches an input line
     if the regular expression (RE) in the pattern matches the input line
     without its trailing newline.  An empty expression matches every line.
     Each input line that matches at least one of the patterns is written to
     the standard output.

     grep is used for simple patterns and basic regular expressions (BREs);
     egrep can handle extended regular expressions (EREs).  See re_format(7)
     for more information on regular expressions.  fgrep is quicker than both
     grep and egrep, but can only handle fixed patterns (i.e. it does not
     interpret regular expressions).  Patterns may consist of one or more
     lines, allowing any of the pattern lines to match a portion of the input.

     zgrep, zegrep, and zfgrep act like grep, egrep, and fgrep, respectively,
     but accept input files compressed with the compress(1) or gzip(1)
     compression utilities.

     The following options are available:

     -A num, --after-context=num
             Print num lines of trailing context after each match.  See also
             the -B and -C options.

     -a, --text
             Treat all files as ASCII text.  Normally grep will simply print
             ``Binary file ... matches'' if files contain binary characters.
             Use of this option forces grep to output lines matching the
             specified pattern.

     -B num, --before-context=num
             Print num lines of leading context before each match.  See also
             the -A and -C options.

     -b, --byte-offset
             The offset in bytes of a matched pattern is displayed in front of
             the respective matched line.

     -C[num, --context=num]
             Print num lines of leading and trailing context surrounding each
             match.  The default is 2 and is equivalent to -A 2 -B 2.  Note:
             no whitespace may be given between the option and its argument.

     -c, --count
             Only a count of selected lines is written to standard output.

     --colour=[when, --color=[when]]
             Mark up the matching text with the expression stored in
             GREP_COLOR environment variable.  The possible values of when can
             be `never', `always' or `auto'.

     -D action, --devices=action
             Specify the demanded action for devices, FIFOs and sockets.  The
             default action is `read', which means, that they are read as if
             they were normal files.  If the action is set to `skip', devices
             will be silently skipped.

     -d action, --directories=action
             Specify the demanded action for directories.  It is `read' by
             default, which means that the directories are read in the same
             manner as normal files.  Other possible values are `skip' to
             silently ignore the directories, and `recurse' to read them
             recursively, which has the same effect as the -R and -r option.

     -E, --extended-regexp
             Interpret pattern as an extended regular expression (i.e. force
             grep to behave as egrep).

     -e pattern, --regexp=pattern
             Specify a pattern used during the search of the input: an input
             line is selected if it matches any of the specified patterns.
             This option is most useful when multiple -e options are used to
             specify multiple patterns, or when a pattern begins with a dash
             (`-').

     --exclude
             If specified, it excludes files matching the given filename
             pattern from the search.  Note that --exclude patterns take
             priority over --include patterns, and if no --include pattern is
             specified, all files are searched that are not excluded.
             Patterns are matched to the full path specified, not only to the
             filename component.

     --exclude-dir
             If -R is specified, it excludes directories matching the given
             filename pattern from the search.  Note that --exclude-dir
             patterns take priority over --include-dir patterns, and if no
             --include-dir pattern is specified, all directories are searched
             that are not excluded.

     -F, --fixed-strings
             Interpret pattern as a set of fixed strings (i.e. force grep to
             behave as fgrep).

     -f file, --file=file
             Read one or more newline separated patterns from file.  Empty
             pattern lines match every input line.  Newlines are not
             considered part of a pattern.  If file is empty, nothing is
             matched.

     -G, --basic-regexp
             Interpret pattern as a basic regular expression (i.e. force grep
             to behave as traditional grep).

     -H      Always print filename headers with output lines.

     -h, --no-filename
             Never print filename headers (i.e. filenames) with output lines.

     --help  Print a brief help message.

     -I      Ignore binary files.  This option is equivalent to
             --binary-file=without-match option.

     -i, --ignore-case
             Perform case insensitive matching.  By default, grep is case
             sensitive.

     --include
             If specified, only files matching the given filename pattern are
             searched.  Note that --exclude patterns take priority over
             --include patterns.  Patterns are matched to the full path
             specified, not only to the filename component.

     --include-dir
             If -R is specified, only directories matching the given filename
             pattern are searched.  Note that --exclude-dir patterns take
             priority over --include-dir patterns.

     -J, --bz2decompress
             Decompress the bzip2(1) compressed file before looking for the
             text.

     -L, --files-without-match
             Only the names of files not containing selected lines are written
             to standard output.  Pathnames are listed once per file searched.
             If the standard input is searched, the string ``(standard
             input)'' is written.

     -l, --files-with-matches
             Only the names of files containing selected lines are written to
             standard output.  grep will only search a file until a match has
             been found, making searches potentially less expensive.
             Pathnames are listed once per file searched.  If the standard
             input is searched, the string ``(standard input)'' is written.

     --mmap  Use mmap(2) instead of read(2) to read input, which can result in
             better performance under some circumstances but can cause
             undefined behaviour.

     -m num, --max-count=num
             Stop reading the file after num matches.

     -n, --line-number
             Each output line is preceded by its relative line number in the
             file, starting at line 1.  The line number counter is reset for
             each file processed.  This option is ignored if -c, -L, -l, or -q
             is specified.

     --null  Prints a zero-byte after the file name.

     -O      If -R is specified, follow symbolic links only if they were
             explicitly listed on the command line.  The default is not to
             follow symbolic links.

     -o, --only-matching
             Prints only the matching part of the lines.

     -p      If -R is specified, no symbolic links are followed.  This is the
             default.

     -q, --quiet, --silent
             Quiet mode: suppress normal output.  grep will only search a file
             until a match has been found, making searches potentially less
             expensive.

     -R, -r, --recursive
             Recursively search subdirectories listed.

     -S      If -R is specified, all symbolic links are followed.  The default
             is not to follow symbolic links.

     -s, --no-messages
             Silent mode.  Nonexistent and unreadable files are ignored (i.e.
             their error messages are suppressed).

     -U, --binary
             Search binary files, but do not attempt to print them.

     -V, --version
             Display version information and exit.

     -v, --invert-match
             Selected lines are those not matching any of the specified
             patterns.

     -w, --word-regexp
             The expression is searched for as a word (as if surrounded by
             `[[:<:]]' and `[[:>:]]'; see re_format(7)).

     -x, --line-regexp
             Only input lines selected against an entire fixed string or
             regular expression are considered to be matching lines.

     -y      Equivalent to -i.  Obsoleted.

     -Z, -z, --decompress
             Force grep to behave as zgrep.

     --binary-files=value
             Controls searching and printing of binary files.  Options are
             binary, the default: search binary files but do not print them;
             without-match: do not search binary files; and text: treat all
             files as text.

     --context[=num]
             Print num lines of leading and trailing context.  The default is
             2.

     --line-buffered
             Force output to be line buffered.  By default, output is line
             buffered when standard output is a terminal and block buffered
             otherwise.

     If no file arguments are specified, the standard input is used.

EXIT STATUS
     The grep utility exits with one of the following values:

     0     One or more lines were selected.
     1     No lines were selected.
     >1    An error occurred.

EXAMPLES
     To find all occurrences of the word `patricia' in a file:

           $ grep 'patricia' myfile

     To find all occurrences of the pattern `.Pp' at the beginning of a line:

           $ grep '^\.Pp' myfile

     The apostrophes ensure the entire expression is evaluated by grep instead
     of by the user's shell.  The caret `^' matches the null string at the
     beginning of a line, and the `\' escapes the `.', which would otherwise
     match any character.

     To find all lines in a file which do not contain the words `foo' or
     `bar':

           $ grep -v -e 'foo' -e 'bar' myfile

     A simple example of an extended regular expression:

           $ egrep '19|20|25' calendar

     Peruses the file `calendar' looking for either 19, 20, or 25.

SEE ALSO
     ed(1), ex(1), gzip(1), sed(1), re_format(7)

STANDARDS
     The grep utility is compliant with the IEEE Std 1003.1-2008 (``POSIX.1'')
     specification.

     The flags [-AaBbCDdGHhIJLmoPRSUVwZ] are extensions to that specification,
     and the behaviour of the -f flag when used with an empty pattern file is
     left undefined.

     All long options are provided for compatibility with GNU versions of this
     utility.

     Historic versions of the grep utility also supported the flags [-ruy].
     This implementation supports those options; however, their use is
     strongly discouraged.

HISTORY
     The grep command first appeared in Version 6 AT&T UNIX.

FreeBSD 11.0-PRERELEASE          July 28, 2010         FreeBSD 11.0-PRERELEASE

NAME | SYNOPSIS | DESCRIPTION | EXIT STATUS | EXAMPLES | SEE ALSO | STANDARDS | HISTORY

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