projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| b1b2c221 WJ |
1 | /* |
| 2 | * Copyright (c) 1987 Regents of the University of California. | |
| 3 | * All rights reserved. | |
| 4 | * | |
| 5 | * Redistribution and use in source and binary forms, with or without | |
| 6 | * modification, are permitted provided that the following conditions | |
| 7 | * are met: | |
| 8 | * 1. Redistributions of source code must retain the above copyright | |
| 9 | * notice, this list of conditions and the following disclaimer. | |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 | * notice, this list of conditions and the following disclaimer in the | |
| 12 | * documentation and/or other materials provided with the distribution. | |
| 13 | * 3. All advertising materials mentioning features or use of this software | |
| 14 | * must display the following acknowledgement: | |
| 15 | * This product includes software developed by the University of | |
| 16 | * California, Berkeley and its contributors. | |
| 17 | * 4. Neither the name of the University nor the names of its contributors | |
| 18 | * may be used to endorse or promote products derived from this software | |
| 19 | * without specific prior written permission. | |
| 20 | * | |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 31 | * SUCH DAMAGE. | |
| 32 | */ | |
| 33 | ||
| 34 | #ifndef lint | |
| 35 | char copyright[] = | |
| 36 | "@(#) Copyright (c) 1987 Regents of the University of California.\n\ | |
| 37 | All rights reserved.\n"; | |
| 38 | #endif /* not lint */ | |
| 39 | ||
| 40 | #ifndef lint | |
| 41 | static char sccsid[] = "@(#)mesg.c 4.7 (Berkeley) 3/1/91"; | |
| 42 | #endif /* not lint */ | |
| 43 | ||
| 44 | /* | |
| 45 | * mesg -- set current tty to accept or | |
| 46 | * forbid write permission. | |
| 47 | * | |
| 48 | * mesg [y] [n] | |
| 49 | * y allow messages | |
| 50 | * n forbid messages | |
| 51 | */ | |
| 52 | ||
| 53 | #include <sys/types.h> | |
| 54 | #include <sys/stat.h> | |
| 55 | #include <stdio.h> | |
| 56 | ||
| 57 | static char *tty; | |
| 58 | ||
| 59 | main(argc, argv) | |
| 60 | int argc; | |
| 61 | char **argv; | |
| 62 | { | |
| 63 | struct stat sbuf; | |
| 64 | char *ttyname(); | |
| 65 | ||
| 66 | if (!(tty = ttyname(2))) { | |
| 67 | fputs("mesg: not a device in /dev.\n", stderr); | |
| 68 | exit(-1); | |
| 69 | } | |
| 70 | if (stat(tty, &sbuf) < 0) { | |
| 71 | perror("mesg"); | |
| 72 | exit(-1); | |
| 73 | } | |
| 74 | if (argc < 2) { | |
| 75 | if (sbuf.st_mode & 020) { | |
| 76 | fputs("is y\n", stderr); | |
| 77 | exit(0); | |
| 78 | } | |
| 79 | fputs("is n\n", stderr); | |
| 80 | exit(1); | |
| 81 | } | |
| 82 | #define OTHER_WRITE 020 | |
| 83 | switch(*argv[1]) { | |
| 84 | case 'y': | |
| 85 | newmode(sbuf.st_mode | OTHER_WRITE); | |
| 86 | exit(0); | |
| 87 | case 'n': | |
| 88 | newmode(sbuf.st_mode &~ OTHER_WRITE); | |
| 89 | exit(1); | |
| 90 | default: | |
| 91 | fputs("usage: mesg [y] [n]\n", stderr); | |
| 92 | exit(-1); | |
| 93 | } | |
| 94 | /*NOTREACHED*/ | |
| 95 | } | |
| 96 | ||
| 97 | newmode(m) | |
| 98 | u_short m; | |
| 99 | { | |
| 100 | if (chmod(tty, m) < 0) { | |
| 101 | perror("mesg"); | |
| 102 | exit(-1); | |
| 103 | } | |
| 104 | } |