comm - compare two sorted files line by line
SYNOPSIS
comm [OPTION]... FILE1 FILE2
DESCRIPTION
Compare sorted files FILE1 and FILE2 line by line.
When FILE1 or FILE2 (not both) is -, read standard input.
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
--total
output a summary
-z, --zero-terminated
line delimiter is NUL, not newline
--help display this help and exit
--version
output version information and exit
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
GNU coreutils online help: [https://www.gnu.org/software/coreutils/] Report any translation bugs to [https://translationproject.org/team/]
SEE ALSO
Full documentation [https://www.gnu.org/software/coreutils/comm] or available locally via: info '(coreutils) comm invocation'
Packaged by Debian (9.7-3) Copyright © 2025 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later [https://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.