GREP(1) 						    BSD 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 prior-
	     ity 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 sym-
	     bolic 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 other-
	     wise.

     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.

BSD
								   July 28, 2010							       BSD