//po4a: entry man manual
////
Copyright (c) 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. All advertising materials mentioning features or use of this software
   must display the following acknowledgement:
	This product includes software developed by the University of
	California, Berkeley and its contributors.
4. 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.

    @(#)look.1	8.1 (Berkeley) 6/14/93
////
= look(1)
:doctype: manpage
:man manual: User Commands
:man source: util-linux {release-version}
:page-layout: base
:command: look

== NAME

look - display lines beginning with a given string

== SYNOPSIS

*look* [options] _string_ [_file_]

== DESCRIPTION

The *look* utility displays any lines in _file_ which contain _string_ as a prefix. As *look* performs a binary search, the lines in _file_ must be sorted (where *sort*(1) was given the same options *-d* and/or *-f* that *look* is invoked with).

If _file_ is not specified, the file _/usr/share/dict/words_ is used, only alphanumeric characters are compared and the case of alphabetic characters is ignored.

== OPTIONS

*-a*, *--alternative*::
Use the alternative dictionary file.

*-d*, *--alphanum*::
Use normal dictionary character set and order, i.e., only blanks and alphanumeric characters are compared. This is on by default if no file is specified.
+
Note that blanks have been added to dictionary character set for compatibility with *sort -d* command since version 2.28.

*-f*, *--ignore-case*::
Ignore the case of alphabetic characters. This is on by default if no file is specified.

*-t*, *--terminate* _character_::
Specify a string termination character, i.e., only the characters in _string_ up to and including the first occurrence of _character_ are compared.

include::man-common/help-version.adoc[]

The *look* utility exits 0 if one or more lines were found and displayed, 1 if no lines were found, and >1 if an error occurred.

== ENVIRONMENT

*WORDLIST*::
Path to a dictionary file. The environment variable has greater priority than the dictionary path defined in the *FILES* segment.

== FILES

_/usr/share/dict/words_::
the dictionary

_/usr/share/dict/web2_::
the alternative dictionary

== HISTORY

The *look* utility appeared in Version 7 AT&T Unix.

== EXAMPLES

....
sort -d /etc/passwd -o /tmp/look.dict
look -t: root:foobar /tmp/look.dict
....

== SEE ALSO

*grep*(1),
*sort*(1)

include::man-common/bugreports.adoc[]

include::man-common/footer.adoc[]

ifdef::translation[]
include::man-common/translation.adoc[]
endif::[]
