50d8d78065
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 $
|
|
.\" $FreeBSD$
|
|
.\" $OpenBSD: grep.1,v 1.38 2010/04/05 06:30:59 jmc Exp $
|
|
.\" Copyright (c) 1980, 1990, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)grep.1 8.3 (Berkeley) 4/18/94
|
|
.\"
|
|
.Dd May 7, 2018
|
|
.Dt GREP 1
|
|
.Os
|
|
.Sh NAME
|
|
.Nm grep , egrep , fgrep , rgrep ,
|
|
.Nd file pattern searcher
|
|
.Sh SYNOPSIS
|
|
.Nm grep
|
|
.Bk -words
|
|
.Op Fl abcdDEFGHhIiLlmnOopqRSsUVvwxz
|
|
.Op Fl A Ar num
|
|
.Op Fl B Ar num
|
|
.Op Fl C Ns Op Ar num
|
|
.Op Fl e Ar pattern
|
|
.Op Fl f Ar file
|
|
.Op Fl Fl binary-files Ns = Ns Ar value
|
|
.Op Fl Fl color Ns Op = Ns Ar when
|
|
.Op Fl Fl colour Ns Op = Ns Ar when
|
|
.Op Fl Fl context Ns Op = Ns Ar num
|
|
.Op Fl Fl label
|
|
.Op Fl Fl line-buffered
|
|
.Op Fl Fl null
|
|
.Op Ar pattern
|
|
.Op Ar
|
|
.Ek
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm 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.
|
|
.Pp
|
|
.Nm grep
|
|
is used for simple patterns and
|
|
basic regular expressions
|
|
.Pq BREs ;
|
|
.Nm egrep
|
|
can handle extended regular expressions
|
|
.Pq EREs .
|
|
See
|
|
.Xr re_format 7
|
|
for more information on regular expressions.
|
|
.Nm fgrep
|
|
is quicker than both
|
|
.Nm grep
|
|
and
|
|
.Nm 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.
|
|
.Pp
|
|
The following options are available:
|
|
.Bl -tag -width indent
|
|
.It Fl A Ar num , Fl Fl after-context Ns = Ns Ar num
|
|
Print
|
|
.Ar num
|
|
lines of trailing context after each match.
|
|
See also the
|
|
.Fl B
|
|
and
|
|
.Fl C
|
|
options.
|
|
.It Fl a , Fl Fl text
|
|
Treat all files as ASCII text.
|
|
Normally
|
|
.Nm
|
|
will simply print
|
|
.Dq Binary file ... matches
|
|
if files contain binary characters.
|
|
Use of this option forces
|
|
.Nm
|
|
to output lines matching the specified pattern.
|
|
.It Fl B Ar num , Fl Fl before-context Ns = Ns Ar num
|
|
Print
|
|
.Ar num
|
|
lines of leading context before each match.
|
|
See also the
|
|
.Fl A
|
|
and
|
|
.Fl C
|
|
options.
|
|
.It Fl b , Fl Fl byte-offset
|
|
The offset in bytes of a matched pattern is
|
|
displayed in front of the respective matched line.
|
|
.It Fl C Ns Op Ar num , Fl Fl context Ns = Ns Ar num
|
|
Print
|
|
.Ar num
|
|
lines of leading and trailing context surrounding each match.
|
|
The default is 2 and is equivalent to
|
|
.Fl A
|
|
.Ar 2
|
|
.Fl B
|
|
.Ar 2 .
|
|
Note:
|
|
no whitespace may be given between the option and its argument.
|
|
.It Fl c , Fl Fl count
|
|
Only a count of selected lines is written to standard output.
|
|
.It Fl Fl colour Ns = Ns Op Ar when , Fl Fl color Ns = Ns Op Ar when
|
|
Mark up the matching text with the expression stored in
|
|
.Ev GREP_COLOR
|
|
environment variable.
|
|
The possible values of when can be `never', `always' or `auto'.
|
|
.It Fl D Ar action , Fl Fl devices Ns = Ns Ar 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.
|
|
.It Fl d Ar action , Fl Fl directories Ns = Ns Ar 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
|
|
.Fl R
|
|
and
|
|
.Fl r
|
|
option.
|
|
.It Fl E , Fl Fl extended-regexp
|
|
Interpret
|
|
.Ar pattern
|
|
as an extended regular expression
|
|
(i.e. force
|
|
.Nm grep
|
|
to behave as
|
|
.Nm egrep ) .
|
|
.It Fl e Ar pattern , Fl Fl regexp Ns = Ns Ar 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
|
|
.Fl e
|
|
options are used to specify multiple patterns,
|
|
or when a pattern begins with a dash
|
|
.Pq Sq - .
|
|
.It Fl Fl exclude
|
|
If specified, it excludes files matching the given
|
|
filename pattern from the search.
|
|
Note that
|
|
.Fl Fl exclude
|
|
and
|
|
.Fl Fl include
|
|
patterns are processed in the order given.
|
|
If a name patches multiple patterns, the latest matching rule wins.
|
|
If no
|
|
.Fl Fl 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.
|
|
.It Fl Fl exclude-dir
|
|
If
|
|
.Fl R
|
|
is specified, it excludes directories matching the
|
|
given filename pattern from the search.
|
|
Note that
|
|
.Fl Fl exclude-dir
|
|
and
|
|
.Fl Fl include-dir
|
|
patterns are processed in the order given.
|
|
If a name patches multiple patterns, the latest matching rule wins.
|
|
If no
|
|
.Fl Fl include-dir
|
|
pattern is specified, all directories are searched that are
|
|
not excluded.
|
|
.It Fl F , Fl Fl fixed-strings
|
|
Interpret
|
|
.Ar pattern
|
|
as a set of fixed strings
|
|
(i.e. force
|
|
.Nm grep
|
|
to behave as
|
|
.Nm fgrep ) .
|
|
.It Fl f Ar file , Fl Fl file Ns = Ns Ar file
|
|
Read one or more newline separated patterns from
|
|
.Ar file .
|
|
Empty pattern lines match every input line.
|
|
Newlines are not considered part of a pattern.
|
|
If
|
|
.Ar file
|
|
is empty, nothing is matched.
|
|
.It Fl G , Fl Fl basic-regexp
|
|
Interpret
|
|
.Ar pattern
|
|
as a basic regular expression
|
|
(i.e. force
|
|
.Nm grep
|
|
to behave as traditional
|
|
.Nm grep ) .
|
|
.It Fl H
|
|
Always print filename headers with output lines.
|
|
.It Fl h , Fl Fl no-filename
|
|
Never print filename headers
|
|
.Pq i.e. filenames
|
|
with output lines.
|
|
.It Fl Fl help
|
|
Print a brief help message.
|
|
.It Fl I
|
|
Ignore binary files.
|
|
This option is equivalent to
|
|
.Fl Fl binary-file Ns = Ns Ar without-match
|
|
option.
|
|
.It Fl i , Fl Fl ignore-case
|
|
Perform case insensitive matching.
|
|
By default,
|
|
.Nm grep
|
|
is case sensitive.
|
|
.It Fl Fl include
|
|
If specified, only files matching the
|
|
given filename pattern are searched.
|
|
Note that
|
|
.Fl Fl include
|
|
and
|
|
.Fl Fl exclude
|
|
patterns are processed in the order given.
|
|
If a name patches multiple patterns, the latest matching rule wins.
|
|
Patterns are matched to the full path specified,
|
|
not only to the filename component.
|
|
.It Fl Fl include-dir
|
|
If
|
|
.Fl R
|
|
is specified, only directories matching the
|
|
given filename pattern are searched.
|
|
Note that
|
|
.Fl Fl include-dir
|
|
and
|
|
.Fl Fl exclude-dir
|
|
patterns are processed in the order given.
|
|
If a name patches multiple patterns, the latest matching rule wins.
|
|
.It Fl L , Fl Fl 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
|
|
.Dq (standard input)
|
|
is written unless a
|
|
.Fl Fl label
|
|
is specified.
|
|
.It Fl l , Fl Fl files-with-matches
|
|
Only the names of files containing selected lines are written to
|
|
standard output.
|
|
.Nm 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
|
|
.Dq (standard input)
|
|
is written unless a
|
|
.Fl Fl label
|
|
is specified.
|
|
.It Fl Fl label
|
|
Label to use in place of
|
|
.Dq (standard input)
|
|
for a file name where a file name would normally be printed.
|
|
This option applies to
|
|
.Fl H ,
|
|
.Fl L ,
|
|
and
|
|
.Fl l .
|
|
.It Fl Fl mmap
|
|
Use
|
|
.Xr mmap 2
|
|
instead of
|
|
.Xr read 2
|
|
to read input, which can result in better performance under some
|
|
circumstances but can cause undefined behaviour.
|
|
.It Fl m Ar num, Fl Fl max-count Ns = Ns Ar num
|
|
Stop reading the file after
|
|
.Ar num
|
|
matches.
|
|
.It Fl n , Fl Fl 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
|
|
.Fl c ,
|
|
.Fl L ,
|
|
.Fl l ,
|
|
or
|
|
.Fl q
|
|
is
|
|
specified.
|
|
.It Fl Fl null
|
|
Prints a zero-byte after the file name.
|
|
.It Fl O
|
|
If
|
|
.Fl R
|
|
is specified, follow symbolic links only if they were explicitly listed
|
|
on the command line.
|
|
The default is not to follow symbolic links.
|
|
.It Fl o, Fl Fl only-matching
|
|
Prints only the matching part of the lines.
|
|
.It Fl p
|
|
If
|
|
.Fl R
|
|
is specified, no symbolic links are followed.
|
|
This is the default.
|
|
.It Fl q , Fl Fl quiet , Fl Fl silent
|
|
Quiet mode:
|
|
suppress normal output.
|
|
.Nm grep
|
|
will only search a file until a match has been found,
|
|
making searches potentially less expensive.
|
|
.It Fl R , Fl r , Fl Fl recursive
|
|
Recursively search subdirectories listed.
|
|
(i.e. force
|
|
.Nm grep
|
|
to behave as
|
|
.Nm rgrep ) .
|
|
.It Fl S
|
|
If
|
|
.Fl R
|
|
is specified, all symbolic links are followed.
|
|
The default is not to follow symbolic links.
|
|
.It Fl s , Fl Fl no-messages
|
|
Silent mode.
|
|
Nonexistent and unreadable files are ignored
|
|
(i.e. their error messages are suppressed).
|
|
.It Fl U , Fl Fl binary
|
|
Search binary files, but do not attempt to print them.
|
|
.It Fl u
|
|
This option has no effect and is provided only for compatibility with GNU grep.
|
|
.It Fl V , Fl Fl version
|
|
Display version information and exit.
|
|
.It Fl v , Fl Fl invert-match
|
|
Selected lines are those
|
|
.Em not
|
|
matching any of the specified patterns.
|
|
.It Fl w , Fl Fl word-regexp
|
|
The expression is searched for as a word (as if surrounded by
|
|
.Sq [[:<:]]
|
|
and
|
|
.Sq [[:>:]] ;
|
|
see
|
|
.Xr re_format 7 ) .
|
|
.It Fl x , Fl Fl line-regexp
|
|
Only input lines selected against an entire fixed string or regular
|
|
expression are considered to be matching lines.
|
|
.It Fl y
|
|
Equivalent to
|
|
.Fl i .
|
|
Obsoleted.
|
|
.It Fl z , Fl Fl null-data
|
|
Treat input and output data as sequences of lines terminated by a
|
|
zero-byte instead of a newline.
|
|
.It Fl Fl binary-files Ns = Ns Ar value
|
|
Controls searching and printing of binary files.
|
|
Options are
|
|
.Ar binary ,
|
|
the default: search binary files but do not print them;
|
|
.Ar without-match :
|
|
do not search binary files;
|
|
and
|
|
.Ar text :
|
|
treat all files as text.
|
|
.Sm off
|
|
.It Fl Fl context Op = Ar num
|
|
.Sm on
|
|
Print
|
|
.Ar num
|
|
lines of leading and trailing context.
|
|
The default is 2.
|
|
.It Fl Fl line-buffered
|
|
Force output to be line buffered.
|
|
By default, output is line buffered when standard output is a terminal
|
|
and block buffered otherwise.
|
|
.El
|
|
.Pp
|
|
If no file arguments are specified, the standard input is used.
|
|
Additionally,
|
|
.Dq -
|
|
may be used in place of a file name, anywhere that a file name is accepted, to
|
|
read from standard input.
|
|
This includes both
|
|
.Fl f
|
|
and file arguments.
|
|
.Sh EXIT STATUS
|
|
The
|
|
.Nm grep
|
|
utility exits with one of the following values:
|
|
.Pp
|
|
.Bl -tag -width flag -compact
|
|
.It Li 0
|
|
One or more lines were selected.
|
|
.It Li 1
|
|
No lines were selected.
|
|
.It Li \*(Gt1
|
|
An error occurred.
|
|
.El
|
|
.Sh EXAMPLES
|
|
To find all occurrences of the word
|
|
.Sq patricia
|
|
in a file:
|
|
.Pp
|
|
.Dl $ grep 'patricia' myfile
|
|
.Pp
|
|
To find all occurrences of the pattern
|
|
.Ql .Pp
|
|
at the beginning of a line:
|
|
.Pp
|
|
.Dl $ grep '^\e.Pp' myfile
|
|
.Pp
|
|
The apostrophes ensure the entire expression is evaluated by
|
|
.Nm grep
|
|
instead of by the user's shell.
|
|
The caret
|
|
.Ql ^
|
|
matches the null string at the beginning of a line,
|
|
and the
|
|
.Ql \e
|
|
escapes the
|
|
.Ql \&. ,
|
|
which would otherwise match any character.
|
|
.Pp
|
|
To find all lines in a file which do not contain the words
|
|
.Sq foo
|
|
or
|
|
.Sq bar :
|
|
.Pp
|
|
.Dl $ grep -v -e 'foo' -e 'bar' myfile
|
|
.Pp
|
|
A simple example of an extended regular expression:
|
|
.Pp
|
|
.Dl $ egrep '19|20|25' calendar
|
|
.Pp
|
|
Peruses the file
|
|
.Sq calendar
|
|
looking for either 19, 20, or 25.
|
|
.Sh SEE ALSO
|
|
.Xr ed 1 ,
|
|
.Xr ex 1 ,
|
|
.Xr sed 1 ,
|
|
.Xr re_format 7
|
|
.Sh STANDARDS
|
|
The
|
|
.Nm
|
|
utility is compliant with the
|
|
.St -p1003.1-2008
|
|
specification.
|
|
.Pp
|
|
The flags
|
|
.Op Fl AaBbCDdGHhILmoPRSUVw
|
|
are extensions to that specification, and the behaviour of the
|
|
.Fl f
|
|
flag when used with an empty pattern file is left undefined.
|
|
.Pp
|
|
All long options are provided for compatibility with
|
|
GNU versions of this utility.
|
|
.Pp
|
|
Historic versions of the
|
|
.Nm grep
|
|
utility also supported the flags
|
|
.Op Fl ruy .
|
|
This implementation supports those options;
|
|
however, their use is strongly discouraged.
|
|
.Sh HISTORY
|
|
The
|
|
.Nm grep
|
|
command first appeared in
|
|
.At v6 .
|