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 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

-a, --alternative
    Use the alternative dictionary file.

-d, --alphanum
    Use normal dictionary character set and order, i.e. only alphanumeric characters are compared. (This is on by default if no file is specified.)

-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 information and exit.

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.

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

FILES

/usr/share/dict/words
    the dictionary

/usr/share/dict/web2
    the alternative dictionary

SEE ALSO
grep(1), sort(1)

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

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

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