NetBSD/usr.bin/mesg/mesg.c

111 lines
3.3 KiB
C

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1987 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "from: @(#)mesg.c 4.7 (Berkeley) 3/1/91";*/
static char rcsid[] = "$Id: mesg.c,v 1.3 1994/05/17 04:15:59 cgd Exp $";
#endif /* not lint */
/*
* mesg -- set current tty to accept or
* forbid write permission.
*
* mesg [y] [n]
* y allow messages
* n forbid messages
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <stdio.h>
static char *tty;
main(argc, argv)
int argc;
char **argv;
{
struct stat sbuf;
char *ttyname();
if (!(tty = ttyname(2))) {
fputs("mesg: not a device in /dev.\n", stderr);
exit(-1);
}
if (stat(tty, &sbuf) < 0) {
perror("mesg");
exit(-1);
}
if (argc < 2) {
if (sbuf.st_mode & 020) {
fputs("is y\n", stderr);
exit(0);
}
fputs("is n\n", stderr);
exit(1);
}
#define OTHER_WRITE 020
switch(*argv[1]) {
case 'y':
newmode(sbuf.st_mode | OTHER_WRITE);
exit(0);
case 'n':
newmode(sbuf.st_mode &~ OTHER_WRITE);
exit(1);
default:
fputs("usage: mesg [y] [n]\n", stderr);
exit(-1);
}
/*NOTREACHED*/
}
newmode(m)
u_short m;
{
if (chmod(tty, m) < 0) {
perror("mesg");
exit(-1);
}
}