LOOK(1) User Commands LOOK(1)NAMElook - display lines beginning with a given string
SYNOPSISlook [options] string [file]
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 charac‐
ters is ignored.
Use the alternative dictionary file.
Use normal dictionary character set and order, i.e. only
alphanumeric characters are compared. (This is on by default if
no file is specified.)
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
Display help text and exit.
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.
sort -d /etc/passwd -o /tmp/look.dict
look -t: root:foobar /tmp/look.dict
the alternative dictionary
SEE ALSOgrep(1), sort(1)COMPATIBILITY
The original manual page stated that tabs and blank characters partici‐
pated in comparisons when the alphanum option was specified. This was
incorrect, and the current man page matches the historic implementa‐
The look utility appeared in Version 7 AT&T Unix.
The look command is part of the util-linux package and is available
util-linux June 2011 LOOK(1)