NAME

comm - compare two sorted files line by line  

SYNOPSIS

comm [OPTION]... FILE1 FILE2  

DESCRIPTION

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.

-1
suppress column 1 (lines unique to FILE1)
-2
suppress column 2 (lines unique to FILE2)
-3
suppress column 3 (lines that appear in both files)
--check-order
check that the input is correctly sorted, even if all input lines are pairable
--nocheck-order
do not check that the input is correctly sorted
--output-delimiter=STR
separate columns with STR
--help
display this help and exit
--version
output version information and exit

Note, comparisons honor the rules specified by 'LC_COLLATE'.  

EXAMPLES

comm -12 file1 file2
Print only lines present in both file1 and file2.
comm -3 file1 file2
Print lines in file1 not in file2, and vice versa.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/> Report comm translation bugs to <http://translationproject.org/team/>  

AUTHOR

Written by Richard M. Stallman and David MacKenzie.  

COPYRIGHT

Copyright © 2013 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.  

SEE ALSO

join(1), uniq(1)

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 coreutils 'comm invocation'

should give you access to the complete manual.