2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
4 * (c) UNIX System Laboratories, Inc.
5 * All or some portions of this file are derived from material licensed
6 * to the University of California by American Telephone and Telegraph
7 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8 * the permission of UNIX System Laboratories, Inc.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * Modified Fri Mar 10 20:27:19 1995, faith@cs.unc.edu, for Linux
39 * Modified Mon Jul 1 18:14:10 1996, janl@ifi.uio.no, writing to stdout
40 * as suggested by Michael Meskes <meskes@Informatik.RWTH-Aachen.DE>
42 * 1999-02-22 Arkadiusz MiĆkiewicz <misiek@pld.ORG.PL>
43 * - added Native Language Support
45 * 2010-12-01 Marek Polacek <mmpolacek@gmail.com>
54 #include <sys/types.h>
58 #include "closestream.h"
63 #include "pathnames.h"
67 #define IS_ALLOWED 0 /* Receiving messages is allowed. */
68 #define IS_NOT_ALLOWED 1 /* Receiving messages is not allowed. */
69 #define MESG_EXIT_FAILURE 2 /* An error occurred. */
71 static void __attribute__((__noreturn__
)) usage(void)
74 fputs(USAGE_HEADER
, out
);
75 /* TRANSLATORS: this program uses for y and n rpmatch(3),
76 * which means they can be translated. */
78 _(" %s [options] [y | n]\n"), program_invocation_short_name
);
80 fputs(USAGE_SEPARATOR
, out
);
81 fputs(_("Control write access of other users to your terminal.\n"), out
);
83 fputs(USAGE_OPTIONS
, out
);
84 fputs(_(" -v, --verbose explain what is being done\n"), out
);
85 printf(USAGE_HELP_OPTIONS(16));
86 printf(USAGE_MAN_TAIL("mesg(1)"));
91 int main(int argc
, char *argv
[])
95 char ttybuf
[sizeof(_PATH_PROC_FDDIR
) + sizeof(stringify_value(INT_MAX
))];
96 int ch
, fd
, verbose
= FALSE
, ret
;
98 static const struct option longopts
[] = {
99 { "verbose", no_argument
, NULL
, 'v' },
100 { "version", no_argument
, NULL
, 'V' },
101 { "help", no_argument
, NULL
, 'h' },
105 setlocale(LC_ALL
, "");
106 bindtextdomain(PACKAGE
, LOCALEDIR
);
108 close_stdout_atexit();
110 while ((ch
= getopt_long(argc
, argv
, "vVh", longopts
, NULL
)) != -1)
117 print_version(EXIT_SUCCESS
);
121 errtryhelp(EXIT_FAILURE
);
127 fd
= get_terminal_stdfd();
131 exit(MESG_EXIT_FAILURE
);
136 snprintf(ttybuf
, sizeof(ttybuf
), "%s/%d", _PATH_PROC_FDDIR
, fd
);
139 warnx(_("ttyname() failed, attempting to go around using: %s"), tty
);
142 if ((fd
= open(tty
, O_RDONLY
)) < 0)
143 err(MESG_EXIT_FAILURE
, _("cannot open %s"), tty
);
145 err(MESG_EXIT_FAILURE
, _("stat of %s failed"), tty
);
149 if (sb
.st_mode
& (S_IWGRP
| S_IWOTH
)) {
154 return IS_NOT_ALLOWED
;
157 switch (rpmatch(argv
[0])) {
160 if (fchmod(fd
, sb
.st_mode
| S_IWGRP
) < 0)
162 if (fchmod(fd
, sb
.st_mode
| S_IWGRP
| S_IWOTH
) < 0)
164 err(MESG_EXIT_FAILURE
, _("change %s mode failed"), tty
);
166 puts(_("write access to your terminal is allowed"));
170 if (fchmod(fd
, sb
.st_mode
& ~(S_IWGRP
|S_IWOTH
)) < 0)
171 err(MESG_EXIT_FAILURE
, _("change %s mode failed"), tty
);
173 puts(_("write access to your terminal is denied"));
174 ret
= IS_NOT_ALLOWED
;
176 case RPMATCH_INVALID
:
177 warnx(_("invalid argument: %s"), argv
[0]);
178 errtryhelp(EXIT_FAILURE
);