xref: /onnv-gate/usr/src/cmd/mesg/mesg.c (revision 0:68f95e015346)
1*0Sstevel@tonic-gate /*
2*0Sstevel@tonic-gate  * CDDL HEADER START
3*0Sstevel@tonic-gate  *
4*0Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
5*0Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
6*0Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
7*0Sstevel@tonic-gate  * with the License.
8*0Sstevel@tonic-gate  *
9*0Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10*0Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
11*0Sstevel@tonic-gate  * See the License for the specific language governing permissions
12*0Sstevel@tonic-gate  * and limitations under the License.
13*0Sstevel@tonic-gate  *
14*0Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
15*0Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16*0Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
17*0Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
18*0Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
19*0Sstevel@tonic-gate  *
20*0Sstevel@tonic-gate  * CDDL HEADER END
21*0Sstevel@tonic-gate  */
22*0Sstevel@tonic-gate /*
23*0Sstevel@tonic-gate  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
24*0Sstevel@tonic-gate  * Use is subject to license terms.
25*0Sstevel@tonic-gate  */
26*0Sstevel@tonic-gate 
27*0Sstevel@tonic-gate #pragma ident	"%Z%%M%	%I%	%E% SMI"
28*0Sstevel@tonic-gate 
29*0Sstevel@tonic-gate /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
30*0Sstevel@tonic-gate /*	  All Rights Reserved  	*/
31*0Sstevel@tonic-gate 
32*0Sstevel@tonic-gate 
33*0Sstevel@tonic-gate /*
34*0Sstevel@tonic-gate  * mesg -- set current tty to accept or
35*0Sstevel@tonic-gate  *	forbid write permission.
36*0Sstevel@tonic-gate  *
37*0Sstevel@tonic-gate  *	mesg [-y | -n | y | n]
38*0Sstevel@tonic-gate  *		y allow messages
39*0Sstevel@tonic-gate  *		n forbid messages
40*0Sstevel@tonic-gate  *	return codes
41*0Sstevel@tonic-gate  *		0 if messages are ON or turned ON
42*0Sstevel@tonic-gate  *		1 if messages are OFF or turned OFF
43*0Sstevel@tonic-gate  *		2 if an error occurs
44*0Sstevel@tonic-gate  */
45*0Sstevel@tonic-gate 
46*0Sstevel@tonic-gate #include <stdio.h>
47*0Sstevel@tonic-gate #include <stdlib.h>
48*0Sstevel@tonic-gate #include <unistd.h>
49*0Sstevel@tonic-gate #include <locale.h>
50*0Sstevel@tonic-gate #include <libintl.h>
51*0Sstevel@tonic-gate #include <sys/types.h>
52*0Sstevel@tonic-gate #include <sys/stat.h>
53*0Sstevel@tonic-gate 
54*0Sstevel@tonic-gate static void error(const char *s);
55*0Sstevel@tonic-gate static void newmode(mode_t m);
56*0Sstevel@tonic-gate static void usage(void);
57*0Sstevel@tonic-gate 
58*0Sstevel@tonic-gate static char *tty;
59*0Sstevel@tonic-gate 
60*0Sstevel@tonic-gate int
main(int argc,char * argv[])61*0Sstevel@tonic-gate main(int argc, char *argv[])
62*0Sstevel@tonic-gate {
63*0Sstevel@tonic-gate 	int i, c, r = 0;
64*0Sstevel@tonic-gate 	int action = 0;
65*0Sstevel@tonic-gate 	struct stat sbuf;
66*0Sstevel@tonic-gate 
67*0Sstevel@tonic-gate 	extern int optind;
68*0Sstevel@tonic-gate 
69*0Sstevel@tonic-gate 	(void) setlocale(LC_ALL, "");
70*0Sstevel@tonic-gate #if !defined(TEXT_DOMAIN)		/* Should be defined by cc -D */
71*0Sstevel@tonic-gate #define	TEXT_DOMAIN	"SYS_TEST"	/* Use this only if it weren't */
72*0Sstevel@tonic-gate #endif
73*0Sstevel@tonic-gate 	(void) textdomain(TEXT_DOMAIN);
74*0Sstevel@tonic-gate 
75*0Sstevel@tonic-gate 	/*
76*0Sstevel@tonic-gate 	 * Check stdin, stdout and stderr, in order, for a tty
77*0Sstevel@tonic-gate 	 */
78*0Sstevel@tonic-gate 	for (i = 0; i <= 2; i++) {
79*0Sstevel@tonic-gate 		if ((tty = ttyname(i)) != NULL)
80*0Sstevel@tonic-gate 			break;
81*0Sstevel@tonic-gate 	}
82*0Sstevel@tonic-gate 
83*0Sstevel@tonic-gate 	if (stat(tty, &sbuf) < 0)
84*0Sstevel@tonic-gate 		error("cannot stat");
85*0Sstevel@tonic-gate 
86*0Sstevel@tonic-gate 	if (argc < 2) {
87*0Sstevel@tonic-gate 		if (sbuf.st_mode & (S_IWGRP | S_IWOTH)) {
88*0Sstevel@tonic-gate 			(void) printf("is y\n");
89*0Sstevel@tonic-gate 		} else {
90*0Sstevel@tonic-gate 			r = 1;
91*0Sstevel@tonic-gate 			(void) printf("is n\n");
92*0Sstevel@tonic-gate 		}
93*0Sstevel@tonic-gate 		exit(r);
94*0Sstevel@tonic-gate 	}
95*0Sstevel@tonic-gate 
96*0Sstevel@tonic-gate 	while ((c = getopt(argc, argv, "yn")) != EOF) {
97*0Sstevel@tonic-gate 		switch (c) {
98*0Sstevel@tonic-gate 		case 'y':
99*0Sstevel@tonic-gate 			if (action > 0)
100*0Sstevel@tonic-gate 				usage();
101*0Sstevel@tonic-gate 
102*0Sstevel@tonic-gate 			newmode(S_IRUSR | S_IWUSR | S_IWGRP);
103*0Sstevel@tonic-gate 			action++;
104*0Sstevel@tonic-gate 			break;
105*0Sstevel@tonic-gate 
106*0Sstevel@tonic-gate 		case 'n':
107*0Sstevel@tonic-gate 			if (action > 0)
108*0Sstevel@tonic-gate 				usage();
109*0Sstevel@tonic-gate 
110*0Sstevel@tonic-gate 			newmode(S_IRUSR | S_IWUSR);
111*0Sstevel@tonic-gate 			r = 1;
112*0Sstevel@tonic-gate 			action++;
113*0Sstevel@tonic-gate 			break;
114*0Sstevel@tonic-gate 
115*0Sstevel@tonic-gate 		case '?':
116*0Sstevel@tonic-gate 			usage();
117*0Sstevel@tonic-gate 			break;
118*0Sstevel@tonic-gate 		}
119*0Sstevel@tonic-gate 	}
120*0Sstevel@tonic-gate 
121*0Sstevel@tonic-gate 	/*
122*0Sstevel@tonic-gate 	 * Required for POSIX.2
123*0Sstevel@tonic-gate 	 */
124*0Sstevel@tonic-gate 	if (argc > optind) {
125*0Sstevel@tonic-gate 		if (action > 0)
126*0Sstevel@tonic-gate 			usage();
127*0Sstevel@tonic-gate 
128*0Sstevel@tonic-gate 		switch (*argv[optind]) {
129*0Sstevel@tonic-gate 		case 'y':
130*0Sstevel@tonic-gate 			newmode(S_IRUSR | S_IWUSR | S_IWGRP);
131*0Sstevel@tonic-gate 			break;
132*0Sstevel@tonic-gate 
133*0Sstevel@tonic-gate 		case 'n':
134*0Sstevel@tonic-gate 			newmode(S_IRUSR | S_IWUSR);
135*0Sstevel@tonic-gate 			r = 1;
136*0Sstevel@tonic-gate 			break;
137*0Sstevel@tonic-gate 
138*0Sstevel@tonic-gate 		default:
139*0Sstevel@tonic-gate 			usage();
140*0Sstevel@tonic-gate 			break;
141*0Sstevel@tonic-gate 		}
142*0Sstevel@tonic-gate 	}
143*0Sstevel@tonic-gate 
144*0Sstevel@tonic-gate 	return (r);
145*0Sstevel@tonic-gate }
146*0Sstevel@tonic-gate 
147*0Sstevel@tonic-gate void
error(const char * s)148*0Sstevel@tonic-gate error(const char *s)
149*0Sstevel@tonic-gate {
150*0Sstevel@tonic-gate 	(void) fprintf(stderr, "mesg: ");
151*0Sstevel@tonic-gate 	(void) fprintf(stderr, "%s\n", s);
152*0Sstevel@tonic-gate 	exit(2);
153*0Sstevel@tonic-gate }
154*0Sstevel@tonic-gate 
155*0Sstevel@tonic-gate void
newmode(mode_t m)156*0Sstevel@tonic-gate newmode(mode_t m)
157*0Sstevel@tonic-gate {
158*0Sstevel@tonic-gate 	if (chmod(tty, m) < 0)
159*0Sstevel@tonic-gate 		error("cannot change mode");
160*0Sstevel@tonic-gate }
161*0Sstevel@tonic-gate 
162*0Sstevel@tonic-gate void
usage(void)163*0Sstevel@tonic-gate usage(void)
164*0Sstevel@tonic-gate {
165*0Sstevel@tonic-gate 	(void) fprintf(stderr, gettext("usage: mesg [-y | -n | y | n]\n"));
166*0Sstevel@tonic-gate 	exit(2);
167*0Sstevel@tonic-gate }
168