NAME


comm - print lines common to two files


SYNOPSIS


comm
[-123] file1 file2


DESCRIPTION


Comm
reads
file1
and
file2,
which should be sorted, and produces a three column output:
lines only in
file1,
lines only in
file2,
and lines in both files.
The filename '-' means the standard input.
If there is only one file argument,
file2
refers to the standard input.

The optional arguments -1, -2, and -3 specify the printing of
only the corresponding column.
Thus
comm -3
prints only the lines common to both files, and
comm -12
prints lines which are in either file, but not in both.
The default is -123.


FILES


None


SEE ALSO


diff


DIAGNOSTICS


A message is printed if an input file cannot be opened.


AUTHORS



Debbie Scherrer (Lawrence Berkeley Laboratory)


BUGS


The flags used by this tool are the reverse of those used by the
Unix 'comm'.  In Unix, the flags 1, 2, and 3

suppress
printing of the corresponding column.
Kernighan, on page 126 of 'Software Tools' suggests the
version used above.