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 <https://github.com/util-linux/util-linux/issues>.

AVAILABILITY

       The look command is part of the util-linux package which can be downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>.

util-linux 2.41                                    2025-03-17                                            LOOK(1)