[thirdparty/util-linux.git] / login-utils / mesg.1

.\" Copyright (c) 1987, 1990, 1993
.\"	The Regents of the University of California.  All rights reserved.
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.\" modification, are permitted provided that the following conditions
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.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. 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
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.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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.\"	@(#)mesg.1	8.1 (Berkeley) 6/6/93
.\"
.\" Fri Mar 10 20:31:02 1995, modified for standard man macros,
.\" faith@cs.unc.edu
.\"
.\"
.\" "
.TH MESG 1 "10 March 1995" "Linux 1.2" "Linux Programmer's Manual"
.SH NAME
mesg \- display (do not display) messages from other users
.SH SYNOPSIS
.B mesg [ n ] [ y ]
.SH DESCRIPTION
The
.B mesg
utility is invoked by a users to control write access others have to the
terminal device associated with the standard error output.  If write access
is allowed, then programs such as
.BR talk (1)
and
.BR write (1)
may display messages on the terminal.
.PP
Traditionally, write access is allowed by default.  However, as users
become more conscious of various security risks, there is a trend to remove
write access by default, at least for the primary login shell.  To make
sure your ttys are set the way you want them to be set,
.B mesg
should be executed in your login scripts.
.PP
Options available:
.TP
.B n
Disallows messages.
.TP
.B y
Permits messages to be displayed.
.PP
If no arguments are given,
.B mesg
displays the present message status to the standard error output.
.PP
The
.B mesg
utility exits with one of the following values:
.TP
.I "\ 0"
Messages are allowed.
.TP
.I "\ 1"
Messages are not allowed.
.TP
.I "\>1"
An error has occurred.
.SH FILES
.I /dev/[pt]ty[pq]?
.SH "SEE ALSO"
.BR biff (1),
.BR talk (1),
.BR write (1),
.BR wall (1),
.BR login (1),
.BR xterm (1)
.SH HISTORY
A
.B mesg
command appeared in Version 6 AT&T UNIX.

.SH AVAILABILITY
The mesg command is part of the util-linux-ng package and is available from
ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.
Commit	Line	Data
726f69e2 KZ	1	.\" Copyright (c) 1987, 1990, 1993
	2	.\" The Regents of the University of California. All rights reserved.
	3	.\"
	4	.\" Redistribution and use in source and binary forms, with or without
	5	.\" modification, are permitted provided that the following conditions
	6	.\" are met:
	7	.\" 1. Redistributions of source code must retain the above copyright
	8	.\" notice, this list of conditions and the following disclaimer.
	9	.\" 2. Redistributions in binary form must reproduce the above copyright
	10	.\" notice, this list of conditions and the following disclaimer in the
	11	.\" documentation and/or other materials provided with the distribution.
	12	.\" 3. All advertising materials mentioning features or use of this software
	13	.\" must display the following acknowledgement:
	14	.\" This product includes software developed by the University of
	15	.\" California, Berkeley and its contributors.
	16	.\" 4. Neither the name of the University nor the names of its contributors
	17	.\" may be used to endorse or promote products derived from this software
	18	.\" without specific prior written permission.
	19	.\"
	20	.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	.\" SUCH DAMAGE.
	31	.\"
	32	.\" @(#)mesg.1 8.1 (Berkeley) 6/6/93
	33	.\"
	34	.\" Fri Mar 10 20:31:02 1995, modified for standard man macros,
	35	.\" faith@cs.unc.edu
	36	.\"
	37	.\"
	38	.\" "
	39	.TH MESG 1 "10 March 1995" "Linux 1.2" "Linux Programmer's Manual"
6dbe3af9	40	.SH NAME
726f69e2	41	mesg \- display (do not display) messages from other users
6dbe3af9	42	.SH SYNOPSIS
726f69e2	43	.B mesg [ n ] [ y ]
6dbe3af9	44	.SH DESCRIPTION
726f69e2 KZ	45	The
	46	.B mesg
	47	utility is invoked by a users to control write access others have to the
	48	terminal device associated with the standard error output. If write access
	49	is allowed, then programs such as
	50	.BR talk (1)
	51	and
	52	.BR write (1)
	53	may display messages on the terminal.
	54	.PP
	55	Traditionally, write access is allowed by default. However, as users
	56	become more conscious of various security risks, there is a trend to remove
	57	write access by default, at least for the primary login shell. To make
	58	sure your ttys are set the way you want them to be set,
	59	.B mesg
	60	should be executed in your login scripts.
	61	.PP
	62	Options available:
	63	.TP
	64	.B n
	65	Disallows messages.
	66	.TP
	67	.B y
	68	Permits messages to be displayed.
	69	.PP
	70	If no arguments are given,
	71	.B mesg
	72	displays the present message status to the standard error output.
	73	.PP
	74	The
	75	.B mesg
	76	utility exits with one of the following values:
	77	.TP
	78	.I "\ 0"
	79	Messages are allowed.
	80	.TP
	81	.I "\ 1"
	82	Messages are not allowed.
	83	.TP
	84	.I "\>1"
	85	An error has occurred.
	86	.SH FILES
	87	.I /dev/[pt]ty[pq]?
	88	.SH "SEE ALSO"
	89	.BR biff (1),
	90	.BR talk (1),
	91	.BR write (1),
	92	.BR wall (1),
	93	.BR login (1),
	94	.BR xterm (1)
	95	.SH HISTORY
	96	A
	97	.B mesg
	98	command appeared in Version 6 AT&T UNIX.
86d62711 KZ	99
	100	.SH AVAILABILITY
	101	The mesg command is part of the util-linux-ng package and is available from
	102	ftp://ftp.kernel.org/pub/linux/utils/util-linux-ng/.