1 /* $NetBSD: mesg.c,v 1.6 2003/08/07 11:15:12 agc 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\n\ 41 The Regents of the University of California. All rights reserved.\n"); 42 #endif /* not lint */ 43 44 #ifndef lint 45 #if 0 46 static char sccsid[] = "@(#)mesg.c 8.2 (Berkeley) 1/21/94"; 47 #endif 48 __RCSID("$NetBSD: mesg.c,v 1.6 2003/08/07 11:15:12 agc 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 61 int main __P((int, char **)); 62 63 int 64 main(argc, argv) 65 int argc; 66 char *argv[]; 67 { 68 struct stat sb; 69 char *tty; 70 int ch; 71 72 while ((ch = getopt(argc, argv, "")) != -1) 73 switch (ch) { 74 case '?': 75 default: 76 goto usage; 77 } 78 argc -= optind; 79 argv += optind; 80 81 if ((tty = ttyname(STDERR_FILENO)) == NULL) 82 err(2, "ttyname"); 83 if (stat(tty, &sb) < 0) 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 exit(0); 90 } 91 (void)fprintf(stderr, "is n\n"); 92 exit(1); 93 } 94 95 switch (*argv[0]) { 96 case 'y': 97 if (chmod(tty, sb.st_mode | S_IWGRP) < 0) 98 err(2, "%s", tty); 99 exit(0); 100 case 'n': 101 if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0) 102 err(2, "%s", tty); 103 exit(1); 104 } 105 106 usage: (void)fprintf(stderr, "usage: mesg [y | n]\n"); 107 exit(2); 108 } 109