Manual: gnucomm

COMM(1)							User Commands						     COMM(1)

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: 
       Report any translation bugs to 

SEE ALSO
       join(1), uniq(1)

       Full documentation 
       or available locally via: info '(coreutils) comm invocation'

       Packaged by Ubuntu (9.7-3ubuntu2)
       Copyright © 2025 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.

GNU coreutils 9.7					January 2026						     COMM(1)