comm

PURPOSE

     Selects or rejects lines common to two sorted files.

SYNOPSIS
     comm [ - [ 123 ] ] file1 file2


DESCRIPTION

     The comm  command reads  file1 and  file2 and  writes, by
     default, a  three-column output to standard  output.  The
     columns consist of:

     1.  Lines that are only in file1
     2.  Lines that are only in file2
     3.  Lines that are in both file1 and file2.

     If you specify - (minus) for  one of the file names, comm
     reads  standard input.   Both file1  and file2  should be
     sorted according  to the collating sequence  specified by
     the environment variable NLCTAB (see "ctab" and "sort"),

FLAGS

     -1    Suppresses the  display of the first  column (lines
           in file1).
     -2    Suppresses the display of  the second column (lines
           in file2).
     -3    Suppresses the  display of the third  column (lines
           common to file1 and file2).

     Note:  Specifying -123 does nothing (a noop).

EXAMPLES

     1.  To display the  lines unique to each  file and common
         to both:

           comm  things.to.do  things.done

         If   the  files   "things.to.do"  and   "things.done"
         contain:

                    +---------------+---------------+
                    | things.to.do  | things.done   |
                    +---------------+---------------+
                    |   buy soap    |   2nd revision|
                    |   groceries   |   interview   |
                    |   luncheon    |   luncheon    |
                    |   meeting at 3|   system updat|
                    |   system updat|   tech. review|
                    |   tech. review|   weekly repor|
                    +---------------+---------------+

         then comm displays:

                  2nd revision
           buy soap
           groceries
                  interview
                          luncheon
           meeting at 3
                          system update
                          tech. review
                  weekly report

         The  first column  contains the  lines found  only in
         "things.to.do".  The  second column, indented  with a
         tab  character,   lists  the  lines  found   only  in
         "things.done".  The  third column, indented  with two
         tabs, lists the lines common to both.
     2.  To display the lines that appear in only one file:

           comm  -23  things.to.do things.done

         This suppresses  the second and third  columns of the
         comm  listing.   If the  files  are  the same  as  in
         Example 1, then the following is displayed:

         "
         buy soap
         groceries
         meeting at 3 "

RELATED INFORMATION

     The   following  commands:    "cmp,"   "ctab,"   "diff,"
     "sdiff,"  "sort," and "uniq."

     The environment  miscellaneous facility in  AIX Operating
     System Technical Reference.

     "Overview of International Character Support" in Managing
     the AIX Operating System.