ultrix man page for comm

comm(1) 						      General Commands Manual							   comm(1)

Name
       comm - compare sorted data

Syntax
       comm [-[123]] file1 file2

Description
       The  command  reads file1 and file2, which should be ordered in ASCII collating sequence, and produces a three column output: lines only in
       file1; lines only in file2; and lines in both files.  The file name `-' means the standard input.

Options
       1  Suppresses column one: lines in file1 only.

       2  Suppresses column two: lines in file2 only.

       3  Suppresses column three: lines in file1 and file2.

       Thus -12 prints only the lines common to the two files.	And -23 prints only lines in the first file but not in the second.  Finally,  -123
       is not an option.

See Also
       cmp(1), diff(1), diff3(1), diffmk(1), join(1), uniq(1)

																	   comm(1)