1 /* $NetBSD: mesg.c,v 1.5 1997/08/01 04:32:44 mikel 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by the University of 23 * California, Berkeley and its contributors. 24 * 4. Neither the name of the University nor the names of its contributors 25 * may be used to endorse or promote products derived from this software 26 * without specific prior written permission. 27 * 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 31 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 38 * SUCH DAMAGE. 39 */ 40 41 #include <sys/cdefs.h> 42 43 #ifndef lint 44 __COPYRIGHT("@(#) 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 __RCSID("$NetBSD: mesg.c,v 1.5 1997/08/01 04:32:44 mikel 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 main __P((int, char **)); 66 67 int 68 main(argc, argv) 69 int argc; 70 char *argv[]; 71 { 72 struct stat sb; 73 char *tty; 74 int ch; 75 76 while ((ch = getopt(argc, argv, "")) != -1) 77 switch (ch) { 78 case '?': 79 default: 80 goto usage; 81 } 82 argc -= optind; 83 argv += optind; 84 85 if ((tty = ttyname(STDERR_FILENO)) == NULL) 86 err(2, "ttyname"); 87 if (stat(tty, &sb) < 0) 88 err(2, "%s", tty); 89 90 if (*argv == NULL) { 91 if (sb.st_mode & S_IWGRP) { 92 (void)fprintf(stderr, "is y\n"); 93 exit(0); 94 } 95 (void)fprintf(stderr, "is n\n"); 96 exit(1); 97 } 98 99 switch (*argv[0]) { 100 case 'y': 101 if (chmod(tty, sb.st_mode | S_IWGRP) < 0) 102 err(2, "%s", tty); 103 exit(0); 104 case 'n': 105 if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0) 106 err(2, "%s", tty); 107 exit(1); 108 } 109 110 usage: (void)fprintf(stderr, "usage: mesg [y | n]\n"); 111 exit(2); 112 } 113