look.1

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.\"     @(#)look.1	8.1 (Berkeley) 6/14/93
.\"
.Dd June 14, 1993
.Dt LOOK 1
.Os
.Sh NAME
.Nm look
.Nd display lines beginning with a given string
.Sh SYNOPSIS
.Nm look
.Op Fl dfa
.Op Fl t Ar termchar
.Ar string
.Op Ar file
.Sh DESCRIPTION
The 
.Nm look
utility displays any lines in
.Ar file
which contain
.Ar string
as a prefix.
As
.Nm look
performs a binary search, the lines in
.Ar file
must be sorted (where
.Xr sort 1
got the same options \-d and/or \-f that
.Nm look
is invoked with).
.Pp
If
.Ar file
is not specified, the file
.Pa /usr/share/dict/words
is used, only alphanumeric characters are compared and the case of
alphabetic characters is ignored.
.Pp
Options:
.Bl -tag -width Ds
.It Fl d
Dictionary character set and order, i.e. only alphanumeric characters
are compared.
.It Fl f
Ignore the case of alphabetic characters.
.It Fl a
Use the alternate dictionary
.Pa /usr/share/dict/web2
.It Fl t
Specify a string termination character, i.e. only the characters
in
.Ar string
up to and including the first occurrence of
.Ar termchar
are compared.
.El
.Pp
The
.Nm 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.
.Sh FILES
.Bl -tag -width /usr/share/dict/words -compact
.It Pa /usr/share/dict/words
the dictionary
.It Pa /usr/share/dict/web2
the alternate dictionary
.El
.Sh SEE ALSO
.Xr grep 1 ,
.Xr sort 1
.Sh COMPATIBILITY
The original manual page stated that tabs and blank characters participated
in comparisons when the
.Fl d
option was specified.
This was incorrect and the current man page matches the historic
implementation.
.Sh HISTORY
.Nm Look
appeared in Version 7 AT&T Unix.