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.