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| .\" @(#)look.1 8.1 (Berkeley) 6/14/93 |
| .\" |
| .TH LOOK 1 "June 2011" "util-linux" "User Commands" |
| .SH NAME |
| look \- display lines beginning with a given string |
| .SH SYNOPSIS |
| .B look |
| [options] |
| .IR "string " [ file ] |
| .SH DESCRIPTION |
| The |
| .B look |
| utility displays any lines in |
| .I file |
| which contain |
| .IR string . |
| As |
| .B look |
| performs a binary search, the lines in |
| .I file |
| must be sorted (where |
| .BR sort (1) |
| was given the same options |
| .BR "\-d " and/or " \-f " that |
| .B look |
| is invoked with). |
| .PP |
| If |
| .I file |
| is not specified, the file |
| .I /usr/share/dict/words |
| is used, only alphanumeric characters are compared and the case of |
| alphabetic characters is ignored. |
| .SH OPTIONS |
| .TP |
| .BR \-a , " \-\-alternative" |
| Use the alternative dictionary file. |
| .TP |
| .BR \-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 \fBsort \-d\fR command since version 2.28. |
| .TP |
| .BR \-f , " \-\-ignore\-case" |
| Ignore the case of alphabetic characters. This is on by default if no file is |
| specified. |
| .TP |
| .BR \-t , " \-\-terminate " \fIcharacter\fR |
| Specify a string termination character, i.e. only the characters |
| in \fIstring\fR up to and including the first occurrence of \fIcharacter\fR |
| are compared. |
| .TP |
| .BR \-V , " \-\-version" |
| Display version information and exit. |
| .TP |
| .BR \-h , " \-\-help" |
| Display help text and exit. |
| .PP |
| The |
| .B 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 EXAMPLE |
| .RS |
| .nf |
| sort -d /etc/passwd -o /tmp/look.dict |
| look -t: root:foobar /tmp/look.dict |
| .nf |
| .RE |
| .SH ENVIRONMENT |
| .TP |
| .B WORDLIST |
| Path to a dictionary file. The environment variable has greater priority |
| than the dictionary path defined in FILES segment. |
| .SH FILES |
| .IP "\fB/usr/share/dict/words\fR" 4 |
| the dictionary |
| .IP "\fB/usr/share/dict/web2\fR" 4 |
| the alternative dictionary |
| .SH "SEE ALSO" |
| .BR grep (1), |
| .BR sort (1) |
| .SH HISTORY |
| The |
| .B look |
| utility appeared in Version 7 AT&T Unix. |
| .SH AVAILABILITY |
| The look command is part of the util-linux package and is available from |
| https://www.kernel.org/pub/linux/utils/util-linux/. |