uniq(1) -- Linux man page



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
display this help and exit
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.  


Report bugs to <bug-coreutils@gnu.org>.  


Copyright © 2004 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  


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

should give you access to the complete manual.