COMM(1) User Commands COMM(1)

NAME comm - compare two sorted files line by line


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.

AUTHOR Written by Richard M. Stallman and David MacKenzie.

REPORTING BUGS Report comm bugs to GNU coreutils home page: <> General help using GNU software: <> Report comm translation bugs to <>

COPYRIGHT Copyright © 2010 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later <>. 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.

GNU coreutils 8.4 April 2012 COMM(1)