1.\" $OpenBSD: look.1,v 1.12 2010/09/03 11:09:29 jmc Exp $ 2.\" $NetBSD: look.1,v 1.3 1994/12/23 01:10:59 jtc Exp $ 3.\" 4.\" Copyright (c) 1990, 1993 5.\" The Regents of the University of California. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 1. Redistributions of source code must retain the above copyright 11.\" notice, this list of conditions and the following disclaimer. 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 3. Neither the name of the University nor the names of its contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" @(#)look.1 8.1 (Berkeley) 6/14/93 32.\" 33.Dd $Mdocdate: September 3 2010 $ 34.Dt LOOK 1 35.Os 36.Sh NAME 37.Nm look 38.Nd display lines beginning with a given string 39.Sh SYNOPSIS 40.Nm look 41.Op Fl df 42.Op Fl t Ar termchar 43.Ar string 44.Op Ar file 45.Sh DESCRIPTION 46The 47.Nm 48utility displays any lines in 49.Ar file 50which contain 51.Ar string 52as a prefix. 53As 54.Nm 55performs a binary search, the lines in 56.Ar file 57must be sorted. 58.Pp 59If 60.Ar file 61is not specified, the file 62.Pa /usr/share/dict/words 63is used. 64Only alphanumeric characters are compared and the case of 65alphabetic characters is ignored. 66.Pp 67The options are as follows: 68.Bl -tag -width Ds 69.It Fl d 70Dictionary character set and order, i.e., only alphanumeric characters 71are compared. 72.It Fl f 73Ignore the case of alphabetic characters. 74.It Fl t Ar termchar 75Specify a string termination character, i.e., only the characters 76in 77.Ar string 78up to and including the first occurrence of 79.Ar termchar 80are compared. 81.El 82.Sh FILES 83.Bl -tag -width /usr/share/dict/words -compact 84.It Pa /usr/share/dict/words 85the dictionary 86.El 87.Sh EXIT STATUS 88The 89.Nm 90utility exits 0 if one or more lines were found and displayed, 911 if no lines were found, or \*(Gt1 if an error occurred. 92.Sh SEE ALSO 93.Xr grep 1 , 94.Xr sort 1 95.Sh STANDARDS 96The original manual page stated that tabs and blank characters participated 97in comparisons when the 98.Fl d 99option was specified. 100This was incorrect and the current man page matches the historic 101implementation. 102.Sh HISTORY 103The 104.Nm 105command appeared in 106.At v7 . 107