table of contents
other sections
LOOK(1) | General Commands Manual | LOOK(1) |
NAME¶
look
—
display lines beginning with a given string
SYNOPSIS¶
look |
[-bdf -t
termcharfile ... ] |
DESCRIPTION¶
Thelook
utility displays any lines in
file which contain
string as a prefix.
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:
-b
- Use a binary search on the given word list. If you are ignoring case with
-f
or ignoring non-alphanumeric characters with-d
, the file must be sorted in the same way. Please note that these options are the default if no filename is given. See sort(1) for more information on sorting files. -d
- Dictionary character set and order, i.e., only alphanumeric characters are compared.
-f
- Ignore the case of alphabetic characters.
-t
- Specify a string termination character, i.e., only the characters in string up to and including the first occurrence of termchar are compared.
ENVIRONMENT¶
TheLANG
,
LC_ALL
and
LC_CTYPE
environment variables affect the
execution of the look
utility. Their effect
is described in environ(7).
FILES¶
- /usr/share/dict/words
- the dictionary
EXIT STATUS¶
Thelook
utility exits 0 if one or more lines
were found and displayed, 1 if no lines were found, and >1 if an error
occurred.
COMPATIBILITY¶
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.
look
uses a linear search by default instead
of a binary search, which is what most other implementations use by default.
SEE ALSO¶
grep(1), sort(1)HISTORY¶
Alook
utility appeared in
Version 7 AT&T UNIX.
BUGS¶
Lines are not compared according to the current locale's collating order. Input files must be sorted withLC_COLLATE
set to
‘C
’.July 17, 2004 | Debian |