NAME

comm − select or reject lines common to two sorted files

SYNTAX

comm [ −123 ] file1 file2

DESCRIPTION

The comm command reads file1 and file2, which should be ordered in ASCII collating sequence, and produces a three column output:

•Lines only in file1

•Lines only in file2

•Lines in both files

Flags 1, 2, or 3 suppress printing of the corresponding column.  Thus comm −12 prints only the lines common to the two files; comm −23 prints only lines in the first file but not in the second; comm −123 is a no-op. 

If a − is specified for either file1 or file2, comm reads standard input in place of that file. 

SEE ALSO

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