bsd man page for uniq

UNIQ(1) 						      General Commands Manual							   UNIQ(1)

NAME
       uniq - report repeated lines in a file

SYNOPSIS
       uniq [ -udc [ +n ] [ -n ] ] [ input [ output ] ]

DESCRIPTION
       Uniq  reads  the  input file comparing adjacent lines.  In the normal case, the second and succeeding copies of repeated lines are removed;
       the remainder is written on the output file.  Note that repeated lines must be adjacent in order to be found; see sort(1).  If the -u  flag
       is  used, just the lines that are not repeated in the original file are output.	The -d option specifies that one copy of just the repeated
       lines is to be written.	The normal mode output is the union of the -u and -d mode outputs.

       The -c option supersedes -u and -d and generates an output report in default style but with each line preceded by a count of the number	of
       times it occurred.

       The n arguments specify skipping an initial portion of each line in the comparison:

       -n      The  first n fields together with any blanks before each are ignored.  A field is defined as a string of non-space, non-tab charac-
	       ters separated by tabs and spaces from its neighbors.

       +n      The first n characters are ignored.  Fields are skipped before characters.

SEE ALSO
       sort(1), comm(1)

7th Edition							  April 29, 1985							   UNIQ(1)