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