1.\"	$NetBSD: look.1,v 1.10 2017/07/03 21:34:20 wiz Exp $
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 30.\"     @(#)look.1	8.1 (Berkeley) 6/14/93
 31.\"
 32.Dd June 14, 1993
 33.Dt LOOK 1
 34.Os
 35.Sh NAME
 36.Nm look
 37.Nd display lines beginning with a given string
 38.Sh SYNOPSIS
 39.Nm
 40.Op Fl df
 41.Op Fl t Ar termchar
 42.Ar string
 43.Op Ar file
 44.Sh DESCRIPTION
 45The
 46.Nm
 47utility displays any lines in
 48.Ar file
 49which contain
 50.Ar string
 51as a prefix.
 52As
 53.Nm
 54performs a binary search, the lines in
 55.Ar file
 56must be sorted.
 57.Pp
 58If
 59.Ar file
 60is not specified, the file
 61.Pa /usr/share/dict/words
 62is used, only alphanumeric characters are compared and the case of
 63alphabetic characters is ignored.
 64.Pp
 65Options:
 66.Bl -tag -width Ds
 67.It Fl d
 68Dictionary character set and order, i.e. only alphanumeric characters
 69are compared.
 70.It Fl f
 71Ignore the case of alphabetic characters.
 72.It Fl t
 73Specify a string termination character, i.e. only the characters
 74in
 75.Ar string
 76up to and including the first occurrence of
 77.Ar termchar
 78are compared.
 79.El
 80.Pp
 81The
 82.Nm
 83utility exits 0 if one or more lines were found and displayed,
 841 if no lines were found, and >1 if an error occurred.
 85.Sh FILES
 86.Bl -tag -width /usr/share/dict/words -compact
 87.It Pa /usr/share/dict/words
 88the dictionary
 89.El
 90.Sh COMPATIBILITY
 91The original manual page stated that tabs and blank characters participated
 92in comparisons when the
 93.Fl d
 94option was specified.
 95This was incorrect and the current man page matches the historic
 96implementation.
 97.Sh SEE ALSO
 98.Xr grep 1 ,
 99.Xr sort 1
100.Sh HISTORY
101.Nm
102appeared in
103.At v7 .