NAME
comm —
select or reject lines common to
two files
SYNOPSIS
DESCRIPTION
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.
-
-
- -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.
EXIT STATUS
The
comm utility exits 0 on success, and >0 if an
error occurs.
SEE ALSO
cmp(1),
diff(1),
sort(1),
uniq(1)
STANDARDS
The
comm utility conforms to
IEEE Std
1003.2-1992 (“POSIX.2”).