comm [OPTION]... FILE1 FILE2

Compare sorted files FILE1 and FILE2 line by line.

With  no  options,  produce three-column output.  Column one contains lines unique to FILE1, column two con-
tains lines unique to FILE2, and column three contains lines common to both files.

-1     suppress lines unique to FILE1 
-2     suppress lines unique to FILE2

-3     suppress lines that appear in both files

--help display this help and exit

--version output version information and exit