In (info "(coreutils)comm invocation"), after: 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. Columns are separated by a single TAB character.
The options `-1', `-2', and `-3' suppress printing of the corresponding columns. Also see *note Common options::. Please add: If two of them are used, the separator is no longer needed and will not be printed. _______________________________________________ Bug-coreutils mailing list Bug-coreutils@gnu.org http://lists.gnu.org/mailman/listinfo/bug-coreutils