2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * @(#) Copyright (c) 1987, 1993 The Regents of the University of California. All rights reserved.
35 * @(#)mesg.c 8.2 (Berkeley) 1/21/94
36 * $FreeBSD: src/usr.bin/mesg/mesg.c,v 1.4 1999/08/28 01:03:59 peter Exp $
37 * $DragonFly: src/usr.bin/mesg/mesg.c,v 1.5 2005/03/04 10:34:39 liamfoy Exp $
40 #include <sys/types.h>
48 static void usage(void);
51 main(int argc
, char **argv
)
57 while ((ch
= getopt(argc
, argv
, "")) != -1)
66 if ((tty
= ttyname(STDIN_FILENO
)) == NULL
&&
67 (tty
= ttyname(STDOUT_FILENO
)) == NULL
&&
68 (tty
= ttyname(STDERR_FILENO
)) == NULL
)
69 err(2, "ttyname failed");
70 if (stat(tty
, &sb
) < 0)
74 if (sb
.st_mode
& S_IWGRP
) {
75 fprintf(stdout
, "is y\n");
78 fprintf(stdout
, "is n\n");
84 if (chmod(tty
, sb
.st_mode
| S_IWGRP
) < 0)
88 if (chmod(tty
, sb
.st_mode
& ~S_IWGRP
) < 0)
100 fprintf(stderr
, "usage: mesg [y | n]\n");