NAME

comm − select or reject lines common to two sorted files

SYNOPSIS

comm [ − [ 123 ] ] file1 file2

DESCRIPTION

Comm reads file1 and file2, which should be ordered in ASCII collating sequence (see sort(1)), and produces a three-column output: lines only in file1; lines only in file2; and lines in both files. The file name − means the standard input. 

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. 

EXAMPLES

The following command prints all lines common to the files green and yellow:

comm -12 green yellow

Note that green and yellow must be ordered in ASCII collating sequence. 

SEE ALSO

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

INTERNATIONAL SUPPORT

8- and 16-bit data, 8-bit file names, messages. 

Hewlett-Packard Company  —  May 11, 2021