LOOK
Section: User Commands  (1)
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BSD mandoc
 
NAME
look
 - display lines beginning with a given string
 
SYNOPSIS
[-
bdf
]
[-
t termchar
]
string
[
file ...
]
 
DESCRIPTION
The
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
utility.
Their effect is described in
environ(7).
 
FILES
- /usr/share/dict/words
 - 
the dictionary
 
 
EXIT STATUS
The
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.
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
utility appeared in
AT&T System
v7 .
 
BUGS
Lines are not compared according to the current locale's collating
order.
Input files must be sorted with
LC_COLLATE
set to
`C'
 Index
- NAME
 - 
 - SYNOPSIS
 - 
 - DESCRIPTION
 - 
 - ENVIRONMENT
 - 
 - FILES
 - 
 - EXIT STATUS
 - 
 - COMPATIBILITY
 - 
 - SEE ALSO
 - 
 - HISTORY
 - 
 - BUGS
 - 
 
      
      
      
      
   
      
      
         
            
            © Andrew Scott 2006 -
            2025, 
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