source: MondoRescue/branches/2.2.2/mindi-busybox/networking/hostname.c@ 1247

/* vi: set sw=4 ts=4: */
/*
 * $Id: hostname.c,v 1.36 2003/07/14 21:21:01 andersen Exp $
 * Mini hostname implementation for busybox
 *
 * Copyright (C) 1999 by Randolph Chung <tausq@debian.org>
 *
 * adjusted by Erik Andersen <andersen@codepoet.org> to remove
 * use of long options and GNU getopt.  Improved the usage info.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <errno.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include "busybox.h"

extern char *optarg; /* in unistd.h */
extern int  optind, opterr, optopt; /* in unistd.h */

static void do_sethostname(char *s, int isfile)
{
    FILE *f;
    char buf[255];

    if (!s)
        return;
    if (!isfile) {
        if (sethostname(s, strlen(s)) < 0) {
            if (errno == EPERM)
                bb_error_msg_and_die("you must be root to change the hostname");
            else
                bb_perror_msg_and_die("sethostname");
        }
    } else {
        f = bb_xfopen(s, "r");
        while (fgets(buf, 255, f) != NULL) {
            if (buf[0] =='#') {
                continue;
            }
            chomp(buf);
            do_sethostname(buf, 0);
        }
#ifdef CONFIG_FEATURE_CLEAN_UP
        fclose(f);
#endif
    }
}

int hostname_main(int argc, char **argv)
{
    int opt;
    int type = 0;
    struct hostent *hp;
    char *filename = NULL;
    char buf[255];
    char *p = NULL;

    if (argc < 1)
        bb_show_usage();

    while ((opt = getopt(argc, argv, "dfisF:")) > 0) {
        switch (opt) {
        case 'd':
        case 'f':
        case 'i':
        case 's':
            type = opt;
            break;
        case 'F':
            filename = optarg;
            break;
        default:
            bb_show_usage();
        }
    }

    /* Output in desired format */
    if (type != 0) {
        gethostname(buf, 255);
        hp = xgethostbyname(buf);
        p = strchr(hp->h_name, '.');
        if (type == 'f') {
            puts(hp->h_name);
        } else if (type == 's') {
            if (p != NULL) {
                *p = 0;
            }
            puts(hp->h_name);
        } else if (type == 'd') {
            if (p) puts(p + 1);
        } else if (type == 'i') {
            while (hp->h_addr_list[0]) {
                printf("%s ", inet_ntoa(*(struct in_addr *) (*hp->h_addr_list++)));
            }
            printf("\n");
        }
    }
    /* Set the hostname */
    else if (filename != NULL) {
        do_sethostname(filename, 1);
    } else if (optind < argc) {
        do_sethostname(argv[optind], 0);
    }
    /* Or if all else fails,
     * just print the current hostname */
     else {
        gethostname(buf, 255);
        puts(buf);
    }
    return(0);
}