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Diffstat (limited to 'term-utils/mesg.c')
| -rw-r--r-- | term-utils/mesg.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/term-utils/mesg.c b/term-utils/mesg.c new file mode 100644 index 0000000..cb0b493 --- /dev/null +++ b/term-utils/mesg.c @@ -0,0 +1,185 @@ +/* + * 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; +} |