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/*
* Copyright (c) 1987, 1993
* The 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.
*
* Modified Fri Mar 10 20:27:19 1995, faith@cs.unc.edu, for Linux
* Modified Mon Jul 1 18:14:10 1996, janl@ifi.uio.no, writing to stdout
* as suggested by Michael Meskes <meskes@Informatik.RWTH-Aachen.DE>
*
* 1999-02-22 Arkadiusz Miśkiewicz <misiek@pld.ORG.PL>
* - added Native Language Support
*
* 2010-12-01 Marek Polacek <mmpolacek@gmail.com>
* - cleanups
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <getopt.h>
#include "closestream.h"
#include "nls.h"
#include "c.h"
#include "rpmatch.h"
#include "ttyutils.h"
#include "pathnames.h"
/* exit codes */
#define IS_ALLOWED 0 /* Receiving messages is allowed. */
#define IS_NOT_ALLOWED 1 /* Receiving messages is not allowed. */
#define MESG_EXIT_FAILURE 2 /* An error occurred. */
static void __attribute__((__noreturn__)) usage(void)
{
FILE *out = stdout;
fputs(USAGE_HEADER, out);
/* TRANSLATORS: this program uses for y and n rpmatch(3),
* which means they can be translated. */
fprintf(out,
_(" %s [options] [y | n]\n"), program_invocation_short_name);
fputs(USAGE_SEPARATOR, out);
fputs(_("Control write access of other users to your terminal.\n"), out);
fputs(USAGE_OPTIONS, out);
fputs(_(" -v, --verbose explain what is being done\n"), out);
printf(USAGE_HELP_OPTIONS(16));
printf(USAGE_MAN_TAIL("mesg(1)"));
exit(EXIT_SUCCESS);
}
int main(int argc, char *argv[])
{
struct stat sb;
char *tty;
char ttybuf[sizeof(_PATH_PROC_FDDIR) + sizeof(stringify_value(INT_MAX))];
int ch, fd, verbose = FALSE, ret;
static const struct option longopts[] = {
{ "verbose", no_argument, NULL, 'v' },
{ "version", no_argument, NULL, 'V' },
{ "help", no_argument, NULL, 'h' },
{ NULL, 0, NULL, 0 }
};
setlocale(LC_ALL, "");
bindtextdomain(PACKAGE, LOCALEDIR);
textdomain(PACKAGE);
close_stdout_atexit();
while ((ch = getopt_long(argc, argv, "vVh", longopts, NULL)) != -1)
switch (ch) {
case 'v':
verbose = TRUE;
break;
case 'V':
print_version(EXIT_SUCCESS);
case 'h':
usage();
default:
errtryhelp(EXIT_FAILURE);
}
argc -= optind;
argv += optind;
fd = get_terminal_stdfd();
if (fd < 0) {
if (verbose)
warnx(_("no tty"));
exit(MESG_EXIT_FAILURE);
}
tty = ttyname(fd);
if (!tty) {
snprintf(ttybuf, sizeof(ttybuf), "%s/%d", _PATH_PROC_FDDIR, fd);
tty = ttybuf;
if (verbose)
warnx(_("ttyname() failed, attempting to go around using: %s"), tty);
}
if (!*argv) {
if (stat(tty, &sb))
err(MESG_EXIT_FAILURE, _("stat of %s failed"), tty);
if (sb.st_mode & (S_IWGRP | S_IWOTH)) {
puts(_("is y"));
return IS_ALLOWED;
}
puts(_("is n"));
return IS_NOT_ALLOWED;
}
if ((fd = open(tty, O_RDONLY)) < 0)
err(MESG_EXIT_FAILURE, _("cannot open %s"), tty);
if (fstat(fd, &sb))
err(MESG_EXIT_FAILURE, _("stat of %s failed"), tty);
switch (rpmatch(argv[0])) {
case RPMATCH_YES:
#ifdef USE_TTY_GROUP
if (fchmod(fd, sb.st_mode | S_IWGRP) < 0)
#else
if (fchmod(fd, sb.st_mode | S_IWGRP | S_IWOTH) < 0)
#endif
err(MESG_EXIT_FAILURE, _("change %s mode failed"), tty);
if (verbose)
puts(_("write access to your terminal is allowed"));
ret = IS_ALLOWED;
break;
case RPMATCH_NO:
if (fchmod(fd, sb.st_mode & ~(S_IWGRP|S_IWOTH)) < 0)
err(MESG_EXIT_FAILURE, _("change %s mode failed"), tty);
if (verbose)
puts(_("write access to your terminal is denied"));
ret = IS_NOT_ALLOWED;
break;
case RPMATCH_INVALID:
warnx(_("invalid argument: %s"), argv[0]);
errtryhelp(EXIT_FAILURE);
default:
abort();
}
close(fd);
return ret;
}
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