1 /* $OpenBSD: mesg.c,v 1.4 1997/07/31 14:56:33 flipk Exp $ */ 2 /* $NetBSD: mesg.c,v 1.4 1994/12/23 07:16:32 jtc Exp $ */ 3 4 /* 5 * Copyright (c) 1987, 1993 6 * The Regents of the University of California. All rights reserved. 7 * (c) UNIX System Laboratories, Inc. 8 * All or some portions of this file are derived from material licensed 9 * to the University of California by American Telephone and Telegraph 10 * Co. or Unix System Laboratories, Inc. and are reproduced herein with 11 * the permission of UNIX System Laboratories, Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 */ 41 42 #ifndef lint 43 static char copyright[] = 44 "@(#) Copyright (c) 1987, 1993\n\ 45 The Regents of the University of California. All rights reserved.\n"; 46 #endif /* not lint */ 47 48 #ifndef lint 49 #if 0 50 static char sccsid[] = "@(#)mesg.c 8.2 (Berkeley) 1/21/94"; 51 #endif 52 static char rcsid[] = "$OpenBSD: mesg.c,v 1.4 1997/07/31 14:56:33 flipk Exp $"; 53 #endif /* not lint */ 54 55 #include <sys/types.h> 56 #include <sys/stat.h> 57 58 #include <err.h> 59 #include <errno.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <unistd.h> 64 65 int 66 main(argc, argv) 67 int argc; 68 char *argv[]; 69 { 70 struct stat sb; 71 char *tty; 72 int ch; 73 74 while ((ch = getopt(argc, argv, "")) != -1) 75 switch (ch) { 76 case '?': 77 default: 78 goto usage; 79 } 80 argc -= optind; 81 argv += optind; 82 83 if ((tty = ttyname(STDERR_FILENO)) == NULL) 84 err(2, "ttyname"); 85 if (stat(tty, &sb) < 0) 86 err(2, "%s", tty); 87 88 if (*argv == NULL) { 89 if (sb.st_mode & S_IWGRP) { 90 (void)fprintf(stderr, "is y\n"); 91 exit(0); 92 } 93 (void)fprintf(stderr, "is n\n"); 94 exit(1); 95 } 96 97 switch (*argv[0]) { 98 case 'y': 99 if (chmod(tty, sb.st_mode | S_IWGRP) < 0) 100 err(2, "%s", tty); 101 exit(0); 102 case 'n': 103 if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0) 104 err(2, "%s", tty); 105 exit(1); 106 } 107 108 usage: (void)fprintf(stderr, "usage: mesg [y | n]\n"); 109 exit(2); 110 } 111