comm(1) - Plan 9 from User Space

| COMM(1) | COMM(1)
| NAME
| comm – select or reject lines common to two sorted files
SYNOPSIS
| `comm` [ `−123` ] file1 file2
DESCRIPTION
| Comm reads file1 and file2, which are in lexicographical order, 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.
Flag `1`, `2`, or `3` suppresses printing of the corresponding column.
EXAMPLE
| `comm −12 file1 file2`
| Print lines common to two sorted files.
SOURCE
| `/usr/lib/plan9/src/cmd/comm.c`
SEE ALSO
| sort(1), cmp(1), diff(1), uniq(1)