Learn the Linux/Unix Command - uniq

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Name

uniq - remove duplicate lines from a sorted file 

Synopsis

uniq [OPTION]... [INPUT [OUTPUT]]  

Description

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.  

See Also

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 uniq

should give you access to the complete manual.