UNIQ

NAME

uniq - remove duplicate lines from a sorted file

uniq [OPTION]... [INPUT [OUTPUT]]

Discard all but one of successive identical lines from INPUT (or standard input), writing to OUTPUT (or standard output).

Mandatory arguments to long options are mandatory for short options too.

-c, --count: prefix lines by the number of occurrences
-d, --repeated: only print duplicate lines
-D, --all-repeated[=delimit-method] print all duplicate lines: delimit-method={none(default),prepend,separate} Delimiting is done with blank lines.
-f, --skip-fields=N: avoid comparing the first N fields
-i, --ignore-case: ignore differences in case when comparing
-s, --skip-chars=N: avoid comparing the first N characters
-u, --unique: only print unique lines
-w, --check-chars=N: compare no more than N characters in lines
--help: display this help and exit
--version: output version information and exit

A field is a run of whitespace, then non-whitespace characters. Fields are skipped before chars.

Written by Richard Stallman and David MacKenzie.