COMM(1) 						    BSD General Commands Manual 						   COMM(1)

NAME

     comm -- select or reject lines common to two files

SYNOPSIS

     comm [-123i] file1 file2

DESCRIPTION

     The comm utility reads file1 and file2, which should be sorted lexically, and produces three text columns as output: lines only in file1;
     lines only in file2; and lines in both files.

     The filename ``-'' means the standard input.

     The following options are available:

     -1      Suppress printing of column 1.

     -2      Suppress printing of column 2.

     -3      Suppress printing of column 3.

     -i      Case insensitive comparison of lines.

     Each column will have a number of tab characters prepended to it equal to the number of lower numbered columns that are being printed.  For
     example, if column number two is being suppressed, lines printed in column number one will not have any tabs preceding them, and lines
     printed in column number three will have one.

     The comm utility assumes that the files are lexically sorted; all characters participate in line comparisons.

DIAGNOSTICS

     The comm utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     cmp(1), diff(1), sort(1), uniq(1)

STANDARDS

     The comm utility conforms to IEEE Std 1003.2-1992 (``POSIX.2'').

HISTORY

     A comm command appeared in Version 4 AT&T UNIX.

BSD
								   June 6, 1993 							       BSD