openbsd-src/usr.bin/mesg/mesg.1

.\"	$OpenBSD: mesg.1,v 1.18 2019/09/06 19:25:08 schwarze Exp $
.\"	$NetBSD: mesg.1,v 1.3 1994/12/23 07:16:31 jtc Exp $
.\"
.\" Copyright (c) 1987, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"	@(#)mesg.1	8.1 (Berkeley) 6/6/93
.\"
.Dd $Mdocdate: September 6 2019 $
.Dt MESG 1
.Os
.Sh NAME
.Nm mesg
.Nd display (do not display) messages from other users
.Sh SYNOPSIS
.Nm mesg
.Op Cm n | Cm y
.Sh DESCRIPTION
The
.Nm mesg
utility is invoked by a user to control write access others
have to the terminal device associated with the standard error
output.
Write access is allowed by default, and programs such as
.Xr talk 1
and
.Xr write 1
may display messages on the terminal.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Cm n
Disallows messages.
.It Cm y
Permits messages to be displayed.
.El
.Pp
If no arguments are given,
.Nm mesg
displays the present message status to the standard error output.
.Sh FILES
.Bl -tag -width /dev/[pt]ty[pq]? -compact
.It Pa /dev/[pt]ty[pq]?
.El
.Sh EXIT STATUS
The
.Nm mesg
utility exits with one of the following values:
.Pp
.Bl -tag -width Ds -offset indent -compact
.It 0
Messages are allowed.
.It 1
Messages are not allowed.
.It \*(Gt1
An error has occurred.
.El
.Sh SEE ALSO
.Xr biff 1 ,
.Xr talk 1 ,
.Xr write 1
.Sh STANDARDS
The
.Nm
utility is compliant with the
.St -p1003.1-2008
specification.
.Sh HISTORY
A
.Nm mesg
command appeared in
.At v1 .