|Original author(s)||Ken Thompson|
|Developer(s)||AT&T Bell Laboratories|
|Initial release||February 1973|
|Operating system||Unix and Unix-like, MSX-DOS|
|License||GNU GPL v3|
The command is a kind of filter program. Typically it is used after
sort. It can also output only the duplicate lines (with the
-d option), or add the number of occurrences of each line (with the
-c option). For example, the following command lists the unique lines in a file, sorted by the number of times each occurs:
sort file | uniq -c | sort -n
First appearing in Version 3 Unix, uniq is now available for a number of different Unix and Unix-like operating systems. The version bundled in GNU coreutils was written by Richard Stallman and David MacKenzie. A uniq command is also part of ASCII's MSX-DOS2 Tools for MSX-DOS version 2.
- McIlroy, M. D. (1987). A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 (PDF) (Technical report). CSTR. Bell Labs. 139.
- MSX-DOS2 Tools User's Manual by ASCII Corporation