.TH COMM 1 "2008-1.01" "pdcore utilities" "User Commands"
.SH NAME
comm \- select or reject lines common to two files
.SH SYNOPSIS
.B comm
[-123] file1 file2
.SH DESCRIPTION
Read 'file1' and 'file2', both of which should be ordered in the current
collating sequence, and produce three text columns as output: lines unique
to 'file1', lines unique to 'file2', and lines common to both files.
.SH OPTIONS
.TP
-1
Suppress output of column one (lines unique to 'file1').
.TP
-2
Suppress output of column two (lines unique to 'file2').
.TP
-3
Suppress output of column three (lines common to both files).
.P
.SH OPERANDS
.TP
file1, file2
Input files. If none provided, or the filename '-' is passed to comm,
standard input will be used.
.SH "AUTHORITATIVE DOCUMENTATION"
<http://www.opengroup.org/onlinepubs/9699919799/utilities/comm.html>
.SH VERSION AND COMPLIANCE
Utility version 1.01
.P
Functional compliance with POSIX:2008 (IEEE Std 1003.1-2008;
Shell and Utilities, Base Specifications Issue 7).
.SH UNLICENSE
This is free and unencumbered software released into the public domain,
provided "as is", without warranty of any kind, express or implied. See the
file UNLICENSE and the website <http://unlicense.org> for further details.