- Uniq
uniq is a
Unix utility which, when fed a text file, outputs the file with adjacent identical lines collapsed to one. It is a kind offilter program . Typically it is used after sort. It can also output only the duplicate lines (with the -d option), or add the number of occurrences of each line (with the -c option).An example: To see the list of lines in a file, sorted by the number of times each occurs::sort file | uniq -c | sort -n
Using uniq like this is common when building pipelines in
shell script s. Be careful, uniq expects its input to be already sorted; sometimes sort -u is what you need.witches
*-u Print only lines which are not repeated in the original file
*-d Don't output lines that are not repeated in the input.
*-c Generate an output report in default style except that each line is preceded by a count of the number of times it occurred. If this option is specified, the -u and -d options are ignored if either or both are also present.
*-i Ignore case differences when comparing lines
*-s Skips a number of characters in a line
*-w Specifies the number of characters to compare in lines, after any characters and fields have been skipped
*--help Displays a help message
*--version Displays version number on stdout and exits.ee also
*
List of Unix programs External links
* [http://www.linuxmanpages.com/man1/uniq.1.php uniq's]
Linux manpage
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