Content-type: text/html; charset=UTF-8 Man page of COMM

COMM

Section: User Commands (1)
Updated: June 2025
Index Return to Main Contents
 

NAME

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

join(1), uniq(1)


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.

 

Index

NAME
SYNOPSIS
DESCRIPTION
EXAMPLES
AUTHOR
REPORTING BUGS
SEE ALSO
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Time: 11:48:41 GMT, September 14, 2026