tldr/pages/common/uniq.md

# uniq

> Output the unique lines from the given input or file.
> Since it does not detect repeated lines unless they are adjacent, we need to sort them first.
> More information: <https://www.gnu.org/software/coreutils/manual/html_node/uniq-invocation.html>.

- Display each line once:

`sort {{file}} | uniq`

- Display only unique lines:

`sort {{file}} | uniq -u`

- Display only duplicate lines:

`sort {{file}} | uniq -d`

- Display number of occurrences of each line along with that line:

`sort {{file}} | uniq -c`

- Display number of occurrences of each line, sorted by the most frequent:

`sort {{file}} | uniq -c | sort -nr`
uniq: add page 2016-01-12 15:08:52 +00:00			`# uniq`

w: split out of common and add -i to osx, uniq: additions, seq: add page 2015-12-29 13:00:40 +00:00			`> Output the unique lines from the given input or file.`
sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`> Since it does not detect repeated lines unless they are adjacent, we need to sort them first.`
uniq: add more information link (#5599) 2021-03-30 14:47:39 +01:00			`> More information: <https://www.gnu.org/software/coreutils/manual/html_node/uniq-invocation.html>.`
uniq: add page 2016-01-12 15:08:52 +00:00
			`- Display each line once:`

sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`sort {{file}} \| uniq`
uniq: add page 2016-01-12 15:08:52 +00:00
			`- Display only unique lines:`

sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`sort {{file}} \| uniq -u`
uniq: add page 2016-01-12 15:08:52 +00:00
			`- Display only duplicate lines:`

sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`sort {{file}} \| uniq -d`
uniq: add page 2016-01-12 15:08:52 +00:00
fix typos using misspell (#1374) 2017-05-12 10:29:18 +01:00			`- Display number of occurrences of each line along with that line:`
uniq: add page 2016-01-12 15:08:52 +00:00
sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`sort {{file}} \| uniq -c`
uniq: add sorting example (#945) This involves another command, but it's such a natural extension of uniq's `-c` functionality that I feel it's warranted to show here. We should probably add a sort to the -c example too, because uniq only deals with sequential line repetitions. 2016-07-10 10:26:13 +01:00
fix typos using misspell (#1374) 2017-05-12 10:29:18 +01:00			`- Display number of occurrences of each line, sorted by the most frequent:`
uniq: add sorting example (#945) This involves another command, but it's such a natural extension of uniq's `-c` functionality that I feel it's warranted to show here. We should probably add a sort to the -c example too, because uniq only deals with sequential line repetitions. 2016-07-10 10:26:13 +01:00
sort uniq first (#954) 'uniq' does not detect repeated lines unless they are adjacent, so we need to sort them 2016-07-15 12:18:37 +01:00			`sort {{file}} \| uniq -c \| sort -nr`