comm(1)               MPE/iX Shell and Utilities               comm(1)
  ______________________________________________________________________

  NAME
       comm -- compare sorted files and show differences

  SYNOPSIS
       comm [-123] file1 file2

  DESCRIPTION
       comm locates identical lines within files sorted in the same col-
       lating sequence, and produces three columns; the first contains
       lines found only in the first file, the second lines only in the
       second file, and the third lines which are in both files.

  Options
       comm accepts the following options:

       -1  suppresses lines that appear only in file1

       -2  suppresses lines that appear only in file2

       -3  suppresses lines that appear both in file1 and file2

       The options suppress individual columns; thus to list only the
       lines common to both files, use

          comm -12

       To find lines which are unique to one file or the other use

          comm -3

       Observe that

          comm -123

       displays nothing.

  DIAGNOSTICS
       Possible exit status values are:

       0  Successful completion.

       1  Failure because of an error opening or reading an input file
          or because of an invalid command line option.

  Messages

       Message:  comm: file "filename": system error
       Cause:    See syserror(3).
       Action:   See syserror(3).

       Message:  strcoll error, cannot malloc space.
       Cause:    There are not enough free system resources to allocate
                 string space.

                                                                       1

  comm(1)               MPE/iX Shell and Utilities               comm(1)
  ______________________________________________________________________

       Action:   Free up more resources.

       Message:  Unknown option "-option"
       Cause:    You specified an option that is not valid for comm.
       Action:   Check the DESCRIPTION section for a list of valid comm
                 options.

  PORTABILITY
       POSIX.2.  x/OPEN Portability Guide 4.0.  All UNIX systems.

  MPE/iX NOTES
       For information on how the current MPE/iX implementation may
       affect the operation of this utility, see Appendix A, MPE/iX
       Implementation Considerations.

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

                                                                       2