NAME¶
look —
display lines beginning with a
given string
SYNOPSIS¶
look |
[-bdf]
[-t
termchar] string
[file ...] |
DESCRIPTION¶
The
look 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¶
The
LANG
,
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¶
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.
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¶
A
look 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 with
LC_COLLATE
set to
‘
C
’.