source: MondoRescue/branches/3.2/mindi-busybox/networking/hostname.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * 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.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//usage:#define hostname_trivial_usage
//usage:       "[OPTIONS] [HOSTNAME | -F FILE]"
//usage:#define hostname_full_usage "\n\n"
//usage:       "Get or set hostname or DNS domain name\n"
//usage:     "\n    -s  Short"
//usage:     "\n    -i  Addresses for the hostname"
//usage:     "\n    -d  DNS domain name"
//usage:     "\n    -f  Fully qualified domain name"
//usage:     "\n    -F FILE Use FILE's content as hostname"
//usage:
//usage:#define hostname_example_usage
//usage:       "$ hostname\n"
//usage:       "sage\n"
//usage:
//usage:#define dnsdomainname_trivial_usage NOUSAGE_STR
//usage:#define dnsdomainname_full_usage ""

#include "libbb.h"

static void do_sethostname(char *s, int isfile)
{
//  if (!s)
//      return;
    if (isfile) {
        parser_t *parser = config_open2(s, xfopen_for_read);
        while (config_read(parser, &s, 1, 1, "# \t", PARSE_NORMAL & ~PARSE_GREEDY)) {
            do_sethostname(s, 0);
        }
        if (ENABLE_FEATURE_CLEAN_UP)
            config_close(parser);
    } else if (sethostname(s, strlen(s))) {
//      if (errno == EPERM)
//          bb_error_msg_and_die(bb_msg_perm_denied_are_you_root);
        bb_perror_msg_and_die("sethostname");
    }
}

/* Manpage circa 2009:
 *
 * hostname [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [--long]
 *      [-i] [--ip-address] [-s] [--short] [-y] [--yp] [--nis]
 *
 * hostname [-v] [-F filename] [--file filename] / [hostname]
 *
 * domainname [-v] [-F filename] [--file filename]  / [name]
 *  { bbox: not supported }
 *
 * nodename [-v] [-F filename] [--file filename] / [name]
 *  { bbox: not supported }
 *
 * dnsdomainname [-v]
 *  { bbox: supported: Linux kernel build needs this }
 * nisdomainname [-v]
 *  { bbox: not supported }
 * ypdomainname [-v]
 *  { bbox: not supported }
 *
 * -a, --alias
 *  Display the alias name of the host (if used).
 *  { bbox: not supported }
 * -d, --domain
 *  Display the name of the DNS domain. Don't use the command
 *  domainname to get the DNS domain name because it will show the
 *  NIS domain name and not the DNS domain name. Use dnsdomainname
 *  instead.
 * -f, --fqdn, --long
 *  Display the FQDN (Fully Qualified Domain Name). A FQDN consists
 *  of a short host name and the DNS domain name. Unless you are
 *  using bind or NIS for host lookups you can change the FQDN and
 *  the DNS domain name (which is part of the FQDN) in the
 *  /etc/hosts file.
 * -i, --ip-address
 *  Display the IP address(es) of the host.
 * -s, --short
 *  Display the short host name. This is the host name cut at the
 *  first dot.
 * -v, --verbose
 *  Be verbose and tell what's going on.
 *  { bbox: supported but ignored }
 * -y, --yp, --nis
 *  Display the NIS domain name. If a parameter is given (or --file
 *  name ) then root can also set a new NIS domain.
 *  { bbox: not supported }
 * -F, --file filename
 *  Read the host name from the specified file. Comments (lines
 *  starting with a `#') are ignored.
 */
int hostname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hostname_main(int argc UNUSED_PARAM, char **argv)
{
    enum {
        OPT_d = 0x1,
        OPT_f = 0x2,
        OPT_i = 0x4,
        OPT_s = 0x8,
        OPT_F = 0x10,
        OPT_dfis = 0xf,
    };

    unsigned opts;
    char *buf;
    char *hostname_str;

#if ENABLE_LONG_OPTS
    applet_long_options =
        "domain\0"     No_argument "d"
        "fqdn\0"       No_argument "f"
    //Enable if seen in active use in some distro:
    //  "long\0"       No_argument "f"
    //  "ip-address\0" No_argument "i"
    //  "short\0"      No_argument "s"
    //  "verbose\0"    No_argument "v"
        "file\0"       No_argument "F"
        ;

#endif
    /* dnsdomainname from net-tools 1.60, hostname 1.100 (2001-04-14),
     * supports hostname's options too (not just -v as manpage says) */
    opts = getopt32(argv, "dfisF:v", &hostname_str);
    argv += optind;
    buf = safe_gethostname();
    if (applet_name[0] == 'd') /* dnsdomainname? */
        opts = OPT_d;

    if (opts & OPT_dfis) {
        /* Cases when we need full hostname (or its part) */
        struct hostent *hp;
        char *p;

        hp = xgethostbyname(buf);
        p = strchrnul(hp->h_name, '.');
        if (opts & OPT_f) {
            puts(hp->h_name);
        } else if (opts & OPT_s) {
            *p = '\0';
            puts(hp->h_name);
        } else if (opts & OPT_d) {
            if (*p)
                puts(p + 1);
        } else /*if (opts & OPT_i)*/ {
            if (hp->h_length == sizeof(struct in_addr)) {
                struct in_addr **h_addr_list = (struct in_addr **)hp->h_addr_list;
                while (*h_addr_list) {
                    printf(h_addr_list[1] ? "%s " : "%s", inet_ntoa(**h_addr_list));
                    h_addr_list++;
                }
                bb_putchar('\n');
            }
        }
    } else if (opts & OPT_F) {
        /* Set the hostname */
        do_sethostname(hostname_str, 1);
    } else if (argv[0]) {
        /* Set the hostname */
        do_sethostname(argv[0], 0);
    } else {
        /* Just print the current hostname */
        puts(buf);
    }

    if (ENABLE_FEATURE_CLEAN_UP)
        free(buf);
    return EXIT_SUCCESS;
}