NAME¶

uniq - report or omit repeated lines

SYNOPSIS¶

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

DESCRIPTION¶

Filter adjacent matching lines from INPUT (or standard input), writing to OUTPUT (or standard output).

With no options, matching lines are merged to the first occurrence.

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, one for each group

-D, --all-repeated[=METHOD]

print all duplicate lines groups can be delimited with an empty line METHOD={none(default),prepend,separate}

-f, --skip-fields=N

avoid comparing the first N fields

--group[=METHOD]

show all items, separating groups with an empty line METHOD={separate(default),prepend,append,both}

-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

-z, --zero-terminated

end lines with 0 byte, not newline

-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 blanks (usually spaces and/or TABs), then non-blank characters. Fields are skipped before chars.

Note: 'uniq' does not detect repeated lines unless they are adjacent. You may want to sort the input first, or use 'sort -u' without 'uniq'. Also, comparisons honor the rules specified by 'LC_COLLATE'.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/> Report uniq translation bugs to <http://translationproject.org/team/>

AUTHOR¶

Written by Richard M. Stallman and David MacKenzie.

COPYRIGHT¶

Copyright © 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.

SEE ALSO¶

comm(1), join(1), sort(1)

The full documentation for uniq is maintained as a Texinfo manual. If the info and uniq programs are properly installed at your site, the command

info coreutils 'uniq invocation'

should give you access to the complete manual.