Compare two sorted files line by line.

Synopsis

comm [OPTION]... FILE1 FILE2

Description

Reads FILE1 and FILE2, which should be sorted, and produces three columns: lines only in FILE1, lines only in FILE2, and lines in both.

Options

-1 Suppress column 1 (lines unique to FILE1).

-2 Suppress column 2 (lines unique to FILE2).

-3 Suppress column 3 (lines that appear in both files).

--help Display help and exit.

Examples

$ comm a.txt b.txt

Show lines unique to each file and lines common to both.

$ comm -12 a.txt b.txt

Show only lines common to both files.

Notes

Inputs must already be sorted (see sort) for correct results.

See Also

diff, sort, join, uniq