/usr/share/dict/words
the dictionary
look1
Display lines beginning with a given string
Usage
look [-df]
[-t
termchar]
string
[file ...]
Overview
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 -
Dictionary character set and order, i.e., only alphanumeric characters are compared.
-
-f, --ignore-case -
Ignore the case of alphabetic characters.
-
-t, --terminate termchar -
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
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.
Examples
Look for lines starting with ‘xylen’ 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
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.
The -a and --alternative flags are ignored for compatibility.
Releases
87 releases since FreeBSD 2.0.5-RELEASE; the text changed 47 times.
- 2.0.5–2.1.7.1
- 2.2.2
- 2.2.5–2.2.9
- 3.0–3.5.1
- 4.0–4.2
- 4.3
- 4.4–4.6.2
- 4.7–4.11
- 5.0–5.1
- 5.2–5.2.1
- 5.3–5.5
- 6.0–6.3
- 6.4
- 7.0
- 7.1
- 7.2
- 7.3
- 7.4
- 8.0
- 8.1
- 8.2
- 8.3
- 8.4
- 9.0
- 9.1
- 9.2
- 9.3
- 10.0
- 10.1
- 10.2
- 10.3
- 10.4
- 11.0
- 11.1
- 11.2
- 11.3
- 11.4
- 12.0
- 12.1
- 12.2
- 12.3
- 12.4
- 13.0–13.2
- 13.3–13.4
- 13.5
- 14.0–14.1
- 14.2–14.5
- 15.0–16.0
--alphanum since FreeBSD 11.0-RELEASE;
--ignore-case since FreeBSD 11.0-RELEASE;
--terminate since FreeBSD 11.0-RELEASE.