LOOK(1) | General Commands Manual | LOOK(1) |
look
— display
lines beginning with a given string
look |
[-df ] [-t
termchar] string
[file ...] |
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.
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.
The following options are available:
-d
,
--alphanum
-f
,
--ignore-case
-t
,
--terminate
termcharThe LANG
, LC_ALL
and LC_CTYPE
environment variables affect the
execution of the look
utility. Their effect is
described in environ(7).
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.
Look for lines starting with
‘xylene
’ in the file
/usr/share/dict/words:
$ look xylen xylene xylenol xylenyl
Same as above, but do not consider any characters in
string beyond the first
‘e
’. Note that
-f
is implicit since we are searching the default
file /usr/share/dict/words:
$ look -t e xylen Xyleborus xylem xylene xylenol xylenyl xyletic
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.
The -a
and
--alternative
flags are ignored for
compatibility.
A look
utility appeared in
Version 7 AT&T UNIX.
Lines are not compared according to the current locale's collating
order. Input files must be sorted with LC_COLLATE
set to ‘C
’.
December 29, 2020 | macOS 14.6 |