LOOK

Section: User Commands (1)
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BSD mandoc

NAME

look - display lines beginning with a given string

SYNOPSIS

look [-dfa ] [-t termchar ] string [file ]

DESCRIPTION

The look utility displays any lines in file which contain string as a prefix. As look performs a binary search, the lines in file must be sorted (where sort(1) got the same options -d and/or -f that look is invoked with).

If file is not specified, the file /usr/share/dict/words is used, only alphanumeric characters are compared and the case of alphabetic characters is ignored.

Options:

-d: Dictionary character set and order, i.e. only alphanumeric characters are compared. (On by default if no file specified).
-f: Ignore the case of alphabetic characters. (On by default if no file specified).
-a: Use the alternate dictionary /usr/share/dict/web2
-t: Specify a string termination character, i.e. only the characters in string up to and including the first occurrence of termchar are compared.

The 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.

FILES

/usr/share/dict/words: the dictionary
/usr/share/dict/web2: the alternate dictionary

COMPATIBILITY

The original manual page stated that tabs and blank characters participated in comparisons when the -d option was specified. This was incorrect and the current man page matches the historic implementation.

HISTORY

Look appeared in Version 7 AT&T Unix.

AVAILABILITY

The look command is part of the util-linux-ng package and is available from ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.