Manual: look

LOOK(1)							User Commands						     LOOK(1)

NAME
       look - display lines beginning with a given string

SYNOPSIS
       look [options] 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) was given 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
       -a, --alternative
	   Use the alternative dictionary file.

       -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 sort -d command since version
	   2.28.

       -f, --ignore-case
	   Ignore the case of alphabetic characters. This is on by default if no file is specified.

       -t, --terminate character
	   Specify a string termination character, i.e., only the characters in string up to and including the first
	   occurrence of character are compared.

       -h, --help
	   Display help text and exit.

       -V, --version
	   Display version and exit.

EXIT STATUS
       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.

ENVIRONMENT
       WORDLIST
	   Path to a dictionary file. The environment variable has greater priority than the dictionary path defined in the
	   FILES segment.

FILES
       /usr/share/dict/words
	   the dictionary

       /usr/share/dict/web2
	   the alternative dictionary

HISTORY
       The look utility appeared in Version 7 AT&T Unix.

EXAMPLES
	   sort -d /etc/passwd -o /tmp/look.dict
	   look -t: root:foobar /tmp/look.dict

SEE ALSO
       grep(1), sort(1)

REPORTING BUGS
       For bug reports, use the issue tracker .

AVAILABILITY
       The look command is part of the util-linux package which can be downloaded from Linux Kernel Archive
       .

util-linux 2.41.3					 2025-12-15						     LOOK(1)