gethostbyname.c

/*
 * $Id$
 *
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    info@iptel.org
 *
 * ser 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 <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <netdb.h>




static char* id="$Id$";
static char* version="gethostbyname 0.1";
static char* help_msg="\
Usage: gethostbyname   [-hV] -n host\n\
Options:\n\
    -n host       host name\n\
    -V            version number\n\
    -h            this help message\n\
";


int main(int argc, char** argv)
{
        char c;
        char* name;
        struct hostent* he;
        unsigned char** h;

        name=0;
        
        opterr=0;
        while ((c=getopt(argc, argv, "n:hV"))!=-1){
                switch(c){
                        case 'n':
                                name=optarg;
                                break;
                        case 'V':
                                printf("version: %s\n", version);
                                printf("%s\n", id);
                                exit(0);
                                break;
                        case 'h':
                                printf("version: %s\n", version);
                                printf("%s", help_msg);
                                exit(0);
                                break;
                        case '?':
                                if (isprint(optopt))
                                        fprintf(stderr, "Unknown option `-%c´\n", optopt);
                                else
                                        fprintf(stderr, "Unknown character `\\x%x´\n", optopt);
                                goto error;
                        case ':':
                                fprintf(stderr, "Option `-%c´ requires an argument.\n",
                                                optopt);
                                goto error;
                                break;
                        default:
                                abort();
                }
        }
        
        if (name==0){
                fprintf(stderr, "Missing domain name (-n name)\n");
                goto error;
        }
        
        he=gethostbyname(name);
        if (he==0) printf("no answer\n");
        else{
                printf("h_name=%s\n", he->h_name);
                for(h=he->h_aliases;*h;h++)
                        printf("   alias=%s\n", *h);
                for(h=he->h_addr_list;*h;h++)
                        printf("   ip=%d.%d.%d.%d\n", (*h)[0],(*h)[1],(*h)[2],(*h)[3] );
        }
        printf("done\n");
        exit(0);
error:
        exit(-1);
}