1 /* 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. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * @(#) Copyright (c) 1987, 1993 The Regents of the University of California. All rights reserved. 39 * @(#)mesg.c 8.2 (Berkeley) 1/21/94 40 * $FreeBSD: src/usr.bin/mesg/mesg.c,v 1.4 1999/08/28 01:03:59 peter Exp $ 41 * $DragonFly: src/usr.bin/mesg/mesg.c,v 1.3 2003/10/04 20:36:49 hmp Exp $ 42 */ 43 44 #include <sys/types.h> 45 #include <sys/stat.h> 46 47 #include <err.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 53 static void usage(void); 54 55 int 56 main(int argc, char **argv) 57 { 58 struct stat sb; 59 char *tty; 60 int ch; 61 62 while ((ch = getopt(argc, argv, "")) != -1) 63 switch (ch) { 64 case '?': 65 default: 66 usage(); 67 } 68 argc -= optind; 69 argv += optind; 70 71 if ((tty = ttyname(STDERR_FILENO)) == NULL) 72 err(1, "ttyname"); 73 if (stat(tty, &sb) < 0) 74 err(1, "%s", tty); 75 76 if (*argv == NULL) { 77 if (sb.st_mode & S_IWGRP) { 78 (void)fprintf(stderr, "is y\n"); 79 exit(0); 80 } 81 (void)fprintf(stderr, "is n\n"); 82 exit(1); 83 } 84 85 switch (*argv[0]) { 86 case 'y': 87 if (chmod(tty, sb.st_mode | S_IWGRP) < 0) 88 err(1, "%s", tty); 89 exit(0); 90 case 'n': 91 if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0) 92 err(1, "%s", tty); 93 exit(1); 94 } 95 96 usage(); 97 return(0); 98 } 99 100 static void 101 usage(void) 102 { 103 (void)fprintf(stderr, "usage: mesg [y | n]\n"); 104 exit(2); 105 } 106