NAME    [Toc]    [Back]

     comm -- select or reject lines common to two files

SYNOPSIS    [Toc]    [Back]

     comm [-123i] 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 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    [Toc]    [Back]

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

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.


FreeBSD 5.2.1			 June 6, 1993			 FreeBSD 5.2.1