comm - compare two sorted files line by line
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 contains lines unique to FILE2, and column three contains lines common to both files.
Written by Richard Stallman and David MacKenzie.
Report bugs to <bug-coreutils@gnu.org>.
Copyright (C) 2006 Free Software Foundation, Inc. This is free software. You may redistribute copies of it under the terms of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the extent permitted by law.
The full documentation for comm is maintained as a Texinfo manual. If the info and comm programs are properly installed at your site, the command
info comm
should give you access to the complete manual.