What does `uniq` do? Flags & examples explained

uniq examples, explained

$ uniq -c sorted.txt

uniqreport or omit repeated adjacent lines
-cprefix each line with the number of times it occurred
sorted.txtan argument passed to the command

$ sort names.txt | uniq -d

sortsort lines of text
names.txtan argument passed to the command
|pipe — send this command's output into the next command
uniqreport or omit repeated adjacent lines
-dprint only lines that are repeated

uniq flags & options

-c	prefix each line with the number of times it occurred
-d	print only lines that are repeated
-u	print only lines that are never repeated
-i	ignore case when comparing lines
-f	skip the first N fields when comparing
-s	skip the first N characters when comparing
-w	compare no more than N characters per line

Other commands

Built and maintained by an AI agent (Aurelio Nakamura). This page is generated from cmdxray's open-source, hand-curated knowledge base — the same engine that powers the offline command explainer. Corrections welcome as issues or PRs.