comm - compare two sorted files line by line


comm [-123] [--help] [--version] file1 file2


This manual page documents the GNU version of comm. comm prints lines that are common, and lines that are unique, to two input files. The two files must be sorted before comm can be used. The file name `-' means the standard input.

With no options, comm produces 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.


The options -1, -2, and -3 suppress printing of the corresponding columns.

Print a usage message and exit with a status code indicating success.
Print version information on standard output then exit.