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