1/* $NetBSD: mesg.c,v 1.7 2005/07/30 16:14:39 christos 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 46static char sccsid[] = "@(#)mesg.c 8.2 (Berkeley) 1/21/94"; 47#endif 48__RCSID("$NetBSD: mesg.c,v 1.7 2005/07/30 16:14:39 christos 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 61int 62main(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 106usage: (void)fprintf(stderr, "Usage: %s [y | n]\n", getprogname()); 107 return 2; 108} 109