1.\" Copyright (c) 1990, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)look.1 8.1 (Berkeley) 6/14/93 33.\" $FreeBSD$ 34.\" 35.Dd July 17, 2004 36.Dt LOOK 1 37.Os 38.Sh NAME 39.Nm look 40.Nd display lines beginning with a given string 41.Sh SYNOPSIS 42.Nm 43.Op Fl df 44.Op Fl t Ar termchar 45.Ar string 46.Op Ar 47.Sh DESCRIPTION 48The 49.Nm 50utility displays any lines in 51.Ar file 52which contain 53.Ar string 54as a prefix. 55As 56.Nm 57performs a binary search, the lines in 58.Ar file 59must be sorted. 60.Pp 61If 62.Ar file 63is not specified, the file 64.Pa /usr/share/dict/words 65is used, only alphanumeric characters are compared and the case of 66alphabetic characters is ignored. 67.Pp 68The following options are available: 69.Bl -tag -width indent 70.It Fl d 71Dictionary character set and order, i.e., only alphanumeric characters 72are compared. 73.It Fl f 74Ignore the case of alphabetic characters. 75.It Fl t 76Specify a string termination character, i.e., only the characters 77in 78.Ar string 79up to and including the first occurrence of 80.Ar termchar 81are compared. 82.El 83.Sh ENVIRONMENT 84The 85.Ev LANG , LC_ALL 86and 87.Ev LC_CTYPE 88environment variables affect the execution of the 89.Nm 90utility. 91Their effect is described in 92.Xr environ 7 . 93.Sh FILES 94.Bl -tag -width /usr/share/dict/words -compact 95.It Pa /usr/share/dict/words 96the dictionary 97.El 98.Sh EXIT STATUS 99The 100.Nm 101utility exits 0 if one or more lines were found and displayed, 1021 if no lines were found, and >1 if an error occurred. 103.Sh COMPATIBILITY 104The original manual page stated that tabs and blank characters participated 105in comparisons when the 106.Fl d 107option was specified. 108This was incorrect and the current man page matches the historic 109implementation. 110.Sh SEE ALSO 111.Xr grep 1 , 112.Xr sort 1 113.Sh HISTORY 114A 115.Nm 116utility appeared in 117.At v7 . 118.Sh BUGS 119Lines are not compared according to the current locale's collating 120order. 121Input files must be sorted with 122.Ev LC_COLLATE 123set to 124.Ql C . 125