24a656c291
A version of this patch was originally sent to me by se@, matching behavior from newer versions of GNU grep. While there have been some differences of opinion on whether stdin should be closed or not after depleting it in process of -f, I've opted to leave stdin open and just let the later matching stuff fail and result in a no-match. I'm not married to the current behavior- it was generally chosen since we are adopting this in particular from GNU grep, and I would like to stay consistent without a strong argument to the contrary. The current behavior isn't technically wrong, it's just fairly unfriendly to the developer-user of grep that may not realize their usage is trivially invalid. Submitted by: se
498 lines
13 KiB
Groff
498 lines
13 KiB
Groff
.\" $NetBSD: grep.1,v 1.2 2011/02/16 01:31:33 joerg Exp $
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.\" $FreeBSD$
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.\" $OpenBSD: grep.1,v 1.38 2010/04/05 06:30:59 jmc Exp $
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.\" Copyright (c) 1980, 1990, 1993
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.\" The Regents of the University of California. All rights reserved.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\" 3. Neither the name of the University nor the names of its contributors
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.\" may be used to endorse or promote products derived from this software
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.\" without specific prior written permission.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\" SUCH DAMAGE.
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.\"
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.\" @(#)grep.1 8.3 (Berkeley) 4/18/94
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.\"
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.Dd May 7, 2018
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.Dt GREP 1
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.Os
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.Sh NAME
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.Nm grep , egrep , fgrep , rgrep ,
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.Nd file pattern searcher
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.Sh SYNOPSIS
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.Nm grep
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.Bk -words
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.Op Fl abcdDEFGHhIiLlmnOopqRSsUVvwxz
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.Op Fl A Ar num
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.Op Fl B Ar num
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.Op Fl C Ns Op Ar num
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.Op Fl e Ar pattern
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.Op Fl f Ar file
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.Op Fl Fl binary-files Ns = Ns Ar value
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.Op Fl Fl color Ns Op = Ns Ar when
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.Op Fl Fl colour Ns Op = Ns Ar when
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.Op Fl Fl context Ns Op = Ns Ar num
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.Op Fl Fl label
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.Op Fl Fl line-buffered
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.Op Fl Fl null
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.Op Ar pattern
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.Op Ar
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.Ek
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.Sh DESCRIPTION
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The
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.Nm grep
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utility searches any given input files,
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selecting lines that match one or more patterns.
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By default, a pattern matches an input line if the regular expression
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(RE) in the pattern matches the input line
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without its trailing newline.
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An empty expression matches every line.
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Each input line that matches at least one of the patterns is written
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to the standard output.
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.Pp
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.Nm grep
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is used for simple patterns and
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basic regular expressions
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.Pq BREs ;
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.Nm egrep
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can handle extended regular expressions
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.Pq EREs .
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See
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.Xr re_format 7
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for more information on regular expressions.
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.Nm fgrep
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is quicker than both
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.Nm grep
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and
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.Nm egrep ,
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but can only handle fixed patterns
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(i.e. it does not interpret regular expressions).
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Patterns may consist of one or more lines,
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allowing any of the pattern lines to match a portion of the input.
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.Pp
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The following options are available:
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.Bl -tag -width indent
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.It Fl A Ar num , Fl Fl after-context Ns = Ns Ar num
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Print
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.Ar num
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lines of trailing context after each match.
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See also the
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.Fl B
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and
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.Fl C
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options.
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.It Fl a , Fl Fl text
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Treat all files as ASCII text.
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Normally
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.Nm
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will simply print
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.Dq Binary file ... matches
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if files contain binary characters.
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Use of this option forces
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.Nm
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to output lines matching the specified pattern.
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.It Fl B Ar num , Fl Fl before-context Ns = Ns Ar num
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Print
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.Ar num
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lines of leading context before each match.
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See also the
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.Fl A
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and
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.Fl C
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options.
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.It Fl b , Fl Fl byte-offset
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The offset in bytes of a matched pattern is
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displayed in front of the respective matched line.
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.It Fl C Ns Op Ar num , Fl Fl context Ns = Ns Ar num
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Print
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.Ar num
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lines of leading and trailing context surrounding each match.
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The default is 2 and is equivalent to
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.Fl A
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.Ar 2
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.Fl B
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.Ar 2 .
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Note:
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no whitespace may be given between the option and its argument.
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.It Fl c , Fl Fl count
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Only a count of selected lines is written to standard output.
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.It Fl Fl colour Ns = Ns Op Ar when , Fl Fl color Ns = Ns Op Ar when
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Mark up the matching text with the expression stored in
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.Ev GREP_COLOR
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environment variable.
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The possible values of when can be `never', `always' or `auto'.
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.It Fl D Ar action , Fl Fl devices Ns = Ns Ar action
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Specify the demanded action for devices, FIFOs and sockets.
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The default action is `read', which means, that they are read
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as if they were normal files.
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If the action is set to `skip', devices will be silently skipped.
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.It Fl d Ar action , Fl Fl directories Ns = Ns Ar action
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Specify the demanded action for directories.
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It is `read' by default, which means that the directories
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are read in the same manner as normal files.
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Other possible values are `skip' to silently ignore the
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directories, and `recurse' to read them recursively, which
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has the same effect as the
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.Fl R
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and
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.Fl r
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option.
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.It Fl E , Fl Fl extended-regexp
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Interpret
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.Ar pattern
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as an extended regular expression
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(i.e. force
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.Nm grep
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to behave as
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.Nm egrep ) .
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.It Fl e Ar pattern , Fl Fl regexp Ns = Ns Ar pattern
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Specify a pattern used during the search of the input:
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an input line is selected if it matches any of the specified patterns.
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This option is most useful when multiple
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.Fl e
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options are used to specify multiple patterns,
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or when a pattern begins with a dash
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.Pq Sq - .
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.It Fl Fl exclude
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If specified, it excludes files matching the given
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filename pattern from the search.
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Note that
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.Fl Fl exclude
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and
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.Fl Fl include
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patterns are processed in the order given.
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If a name patches multiple patterns, the latest matching rule wins.
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If no
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.Fl Fl include
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pattern is specified, all files are searched that are
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not excluded.
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Patterns are matched to the full path specified,
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not only to the filename component.
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.It Fl Fl exclude-dir
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If
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.Fl R
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is specified, it excludes directories matching the
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given filename pattern from the search.
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Note that
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.Fl Fl exclude-dir
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and
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.Fl Fl include-dir
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patterns are processed in the order given.
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If a name patches multiple patterns, the latest matching rule wins.
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If no
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.Fl Fl include-dir
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pattern is specified, all directories are searched that are
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not excluded.
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.It Fl F , Fl Fl fixed-strings
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Interpret
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.Ar pattern
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as a set of fixed strings
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(i.e. force
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.Nm grep
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to behave as
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.Nm fgrep ) .
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.It Fl f Ar file , Fl Fl file Ns = Ns Ar file
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Read one or more newline separated patterns from
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.Ar file .
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Empty pattern lines match every input line.
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Newlines are not considered part of a pattern.
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If
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.Ar file
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is empty, nothing is matched.
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.It Fl G , Fl Fl basic-regexp
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|
Interpret
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.Ar pattern
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as a basic regular expression
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(i.e. force
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.Nm grep
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to behave as traditional
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.Nm grep ) .
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.It Fl H
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Always print filename headers with output lines.
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.It Fl h , Fl Fl no-filename
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|
Never print filename headers
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.Pq i.e. filenames
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with output lines.
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|
.It Fl Fl help
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|
Print a brief help message.
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|
.It Fl I
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Ignore binary files.
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|
This option is equivalent to
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.Fl Fl binary-file Ns = Ns Ar without-match
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option.
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.It Fl i , Fl Fl ignore-case
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|
Perform case insensitive matching.
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|
By default,
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.Nm grep
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is case sensitive.
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.It Fl Fl include
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If specified, only files matching the
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given filename pattern are searched.
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Note that
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.Fl Fl include
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and
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.Fl Fl exclude
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patterns are processed in the order given.
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If a name patches multiple patterns, the latest matching rule wins.
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Patterns are matched to the full path specified,
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not only to the filename component.
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.It Fl Fl include-dir
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|
If
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.Fl R
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is specified, only directories matching the
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given filename pattern are searched.
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Note that
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.Fl Fl include-dir
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and
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.Fl Fl exclude-dir
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patterns are processed in the order given.
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If a name patches multiple patterns, the latest matching rule wins.
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.It Fl L , Fl Fl files-without-match
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|
Only the names of files not containing selected lines are written to
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standard output.
|
|
Pathnames are listed once per file searched.
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|
If the standard input is searched, the string
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.Dq (standard input)
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|
is written unless a
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.Fl Fl label
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is specified.
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|
.It Fl l , Fl Fl files-with-matches
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|
Only the names of files containing selected lines are written to
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standard output.
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|
.Nm grep
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will only search a file until a match has been found,
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making searches potentially less expensive.
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|
Pathnames are listed once per file searched.
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If the standard input is searched, the string
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.Dq (standard input)
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is written unless a
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.Fl Fl label
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is specified.
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|
.It Fl Fl label
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|
Label to use in place of
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.Dq (standard input)
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for a file name where a file name would normally be printed.
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|
This option applies to
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.Fl H ,
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.Fl L ,
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and
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.Fl l .
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|
.It Fl Fl mmap
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|
Use
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.Xr mmap 2
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|
instead of
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|
.Xr read 2
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to read input, which can result in better performance under some
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circumstances but can cause undefined behaviour.
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.It Fl m Ar num, Fl Fl max-count Ns = Ns Ar num
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Stop reading the file after
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.Ar num
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matches.
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.It Fl n , Fl Fl line-number
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Each output line is preceded by its relative line number in the file,
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starting at line 1.
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|
The line number counter is reset for each file processed.
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|
This option is ignored if
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.Fl c ,
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.Fl L ,
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.Fl l ,
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or
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.Fl q
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is
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specified.
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.It Fl Fl null
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Prints a zero-byte after the file name.
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|
.It Fl O
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|
If
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.Fl R
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is specified, follow symbolic links only if they were explicitly listed
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on the command line.
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The default is not to follow symbolic links.
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.It Fl o, Fl Fl only-matching
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Prints only the matching part of the lines.
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.It Fl p
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If
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.Fl R
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is specified, no symbolic links are followed.
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This is the default.
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.It Fl q , Fl Fl quiet , Fl Fl silent
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|
Quiet mode:
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suppress normal output.
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|
.Nm grep
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|
will only search a file until a match has been found,
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making searches potentially less expensive.
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.It Fl R , Fl r , Fl Fl recursive
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|
Recursively search subdirectories listed.
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(i.e. force
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.Nm grep
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to behave as
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.Nm rgrep ) .
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.It Fl S
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If
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.Fl R
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is specified, all symbolic links are followed.
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The default is not to follow symbolic links.
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.It Fl s , Fl Fl no-messages
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Silent mode.
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Nonexistent and unreadable files are ignored
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(i.e. their error messages are suppressed).
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.It Fl U , Fl Fl binary
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Search binary files, but do not attempt to print them.
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.It Fl u
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This option has no effect and is provided only for compatibility with GNU grep.
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.It Fl V , Fl Fl version
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Display version information and exit.
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.It Fl v , Fl Fl invert-match
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Selected lines are those
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.Em not
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matching any of the specified patterns.
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.It Fl w , Fl Fl word-regexp
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The expression is searched for as a word (as if surrounded by
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.Sq [[:<:]]
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and
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.Sq [[:>:]] ;
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see
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.Xr re_format 7 ) .
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.It Fl x , Fl Fl line-regexp
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Only input lines selected against an entire fixed string or regular
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expression are considered to be matching lines.
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.It Fl y
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Equivalent to
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.Fl i .
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Obsoleted.
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.It Fl z , Fl Fl null-data
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Treat input and output data as sequences of lines terminated by a
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zero-byte instead of a newline.
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.It Fl Fl binary-files Ns = Ns Ar value
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Controls searching and printing of binary files.
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Options are
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.Ar binary ,
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the default: search binary files but do not print them;
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.Ar without-match :
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do not search binary files;
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and
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.Ar text :
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treat all files as text.
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.Sm off
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.It Fl Fl context Op = Ar num
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.Sm on
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Print
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.Ar num
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lines of leading and trailing context.
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The default is 2.
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.It Fl Fl line-buffered
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Force output to be line buffered.
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By default, output is line buffered when standard output is a terminal
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and block buffered otherwise.
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.El
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.Pp
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If no file arguments are specified, the standard input is used.
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Additionally,
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.Dq -
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may be used in place of a file name, anywhere that a file name is accepted, to
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read from standard input.
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This includes both
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.Fl f
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and file arguments.
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.Sh EXIT STATUS
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The
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.Nm grep
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utility exits with one of the following values:
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.Pp
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.Bl -tag -width flag -compact
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.It Li 0
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One or more lines were selected.
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.It Li 1
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No lines were selected.
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.It Li \*(Gt1
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An error occurred.
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.El
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.Sh EXAMPLES
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To find all occurrences of the word
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.Sq patricia
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in a file:
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.Pp
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.Dl $ grep 'patricia' myfile
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.Pp
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To find all occurrences of the pattern
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.Ql .Pp
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at the beginning of a line:
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.Pp
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.Dl $ grep '^\e.Pp' myfile
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.Pp
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The apostrophes ensure the entire expression is evaluated by
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.Nm grep
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instead of by the user's shell.
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The caret
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.Ql ^
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matches the null string at the beginning of a line,
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and the
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.Ql \e
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escapes the
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.Ql \&. ,
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which would otherwise match any character.
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.Pp
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To find all lines in a file which do not contain the words
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.Sq foo
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or
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.Sq bar :
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.Pp
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.Dl $ grep -v -e 'foo' -e 'bar' myfile
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.Pp
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|
A simple example of an extended regular expression:
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.Pp
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.Dl $ egrep '19|20|25' calendar
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.Pp
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Peruses the file
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.Sq calendar
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looking for either 19, 20, or 25.
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.Sh SEE ALSO
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|
.Xr ed 1 ,
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.Xr ex 1 ,
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|
.Xr sed 1 ,
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.Xr re_format 7
|
|
.Sh STANDARDS
|
|
The
|
|
.Nm
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|
utility is compliant with the
|
|
.St -p1003.1-2008
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specification.
|
|
.Pp
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|
The flags
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|
.Op Fl AaBbCDdGHhILmoPRSUVw
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are extensions to that specification, and the behaviour of the
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.Fl f
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flag when used with an empty pattern file is left undefined.
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.Pp
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All long options are provided for compatibility with
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GNU versions of this utility.
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.Pp
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Historic versions of the
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.Nm grep
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utility also supported the flags
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.Op Fl ruy .
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This implementation supports those options;
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however, their use is strongly discouraged.
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.Sh HISTORY
|
|
The
|
|
.Nm grep
|
|
command first appeared in
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|
.At v6 .
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