1 /* $NetBSD: mesg.c,v 1.8 2008/07/21 14:19:24 lukem Exp $ */
2
3 /*
4 * Copyright (c) 1987, 1993
5 * The Regents of the University of California. All rights reserved.
6 * (c) UNIX System Laboratories, Inc.
7 * All or some portions of this file are derived from material licensed
8 * to the University of California by American Telephone and Telegraph
9 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10 * the permission of UNIX System Laboratories, Inc.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #include <sys/cdefs.h>
38
39 #ifndef lint
40 __COPYRIGHT("@(#) Copyright (c) 1987, 1993\
41 The Regents of the University of California. All rights reserved.");
42 #endif /* not lint */
43
44 #ifndef lint
45 #if 0
46 static char sccsid[] = "@(#)mesg.c 8.2 (Berkeley) 1/21/94";
47 #endif
48 __RCSID("$NetBSD: mesg.c,v 1.8 2008/07/21 14:19:24 lukem Exp $");
49 #endif /* not lint */
50
51 #include <sys/types.h>
52 #include <sys/stat.h>
53
54 #include <err.h>
55 #include <errno.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60
61 int
main(int argc,char * argv[])62 main(int argc, char *argv[])
63 {
64 struct stat sb;
65 char *tty;
66 int ch;
67
68 setprogname(*argv);
69
70 while ((ch = getopt(argc, argv, "")) != -1)
71 switch (ch) {
72 case '?':
73 default:
74 goto usage;
75 }
76 argc -= optind;
77 argv += optind;
78
79 if ((tty = ttyname(STDIN_FILENO)) == NULL &&
80 (tty = ttyname(STDOUT_FILENO)) == NULL &&
81 (tty = ttyname(STDERR_FILENO)) == NULL)
82 err(2, "ttyname");
83 if (stat(tty, &sb) == -1)
84 err(2, "%s", tty);
85
86 if (*argv == NULL) {
87 if (sb.st_mode & S_IWGRP) {
88 (void)fprintf(stderr, "is y\n");
89 return 0;
90 }
91 (void)fprintf(stderr, "is n\n");
92 return 1;
93 }
94
95 switch (*argv[0]) {
96 case 'y':
97 if (chmod(tty, sb.st_mode | S_IWGRP) == -1)
98 err(2, "%s", tty);
99 return 0;
100 case 'n':
101 if (chmod(tty, sb.st_mode & ~S_IWGRP) == -1)
102 err(2, "%s", tty);
103 return 1;
104 }
105
106 usage: (void)fprintf(stderr, "Usage: %s [y | n]\n", getprogname());
107 return 2;
108 }
109