source: MondoRescue/branches/2.2.8.selinux/mindi-busybox/init/mesg.c@ 2892

/* vi: set sw=4 ts=4: */
/*
 * mesg implementation for busybox
 *
 * Copyright (c) 2002 Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "libbb.h"

#ifdef USE_TTY_GROUP
#define S_IWGRP_OR_S_IWOTH  S_IWGRP
#else
#define S_IWGRP_OR_S_IWOTH  (S_IWGRP | S_IWOTH)
#endif

int mesg_main(int argc, char **argv);
int mesg_main(int argc, char **argv)
{
    struct stat sb;
    const char *tty;
    char c = 0;

    if (--argc == 0
     || (argc == 1 && ((c = **++argv) == 'y' || c == 'n'))
    ) {
        tty = ttyname(STDERR_FILENO);
        if (tty == NULL) {
            tty = "ttyname";
        } else if (stat(tty, &sb) == 0) {
            mode_t m;
            if (argc == 0) {
                puts((sb.st_mode & (S_IWGRP|S_IWOTH)) ? "is y" : "is n");
                return EXIT_SUCCESS;
            }
            m = (c == 'y') ? sb.st_mode | S_IWGRP_OR_S_IWOTH
                           : sb.st_mode & ~(S_IWGRP|S_IWOTH);
            if (chmod(tty, m) == 0) {
                return EXIT_SUCCESS;
            }
        }
        bb_perror_msg_and_die("%s", tty);
    }
    bb_show_usage();
}