NAME    [Toc]    [Back]

     comm - select or reject lines common to two files

SYNOPSIS    [Toc]    [Back]

     comm [-123f] file1 file2

DESCRIPTION    [Toc]    [Back]

     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 options are as follows:

     -1      Suppress printing of column 1.

     -2      Suppress printing of column 2.

     -3      Suppress printing of column 3.

     -f      Fold case in line comparisons.

     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.

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

     The  comm  utility  exits 0 on success or >0 if an error occurred.

SEE ALSO    [Toc]    [Back]

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

STANDARDS    [Toc]    [Back]

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

HISTORY    [Toc]    [Back]

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

OpenBSD      3.6                           June      6,      1993