#include <stdio.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int main(int argc, char** argv)
{
    unsigned int addr;
    struct hostent *hp;
    struct in_addr s;
    int i;

    if(argc != 2)
    {
	fprintf(stderr, "Usage: %s ip-address\n", argv[0]);
	return 1;
    }

    addr = inet_addr(argv[1]);
    if(addr == 0xffffffff && strcmp(argv[1], "255.255.255.255") != 0)
    {
	fprintf(stderr, "Invalid argument: %s\n", argv[1]);
	return 1;
    }

    hp = gethostbyaddr((char *)&addr, 4, AF_INET);
    if(hp == NULL)
    {
	fprintf(stderr, "Can't get a network host entry for %s\n", argv[1]);
	return 1;
    }

    printf("OfficialName: %s\n", hp->h_name);
    printf("Aliases:");
    for(i = 0; hp->h_aliases[i]; i++)
	printf(" %s", hp->h_aliases[i]);
    printf("\n");
    printf("HostAddressType: %d\n", hp->h_addrtype);
    printf("AddressLength: %d\n", hp->h_length);
    printf("Address:");
    for(i = 0; hp->h_addr_list[i]; i++)
    {
	memcpy(&s, hp->h_addr_list[i], 4);
	printf(" %s", inet_ntoa(s));
    }
    printf("\n");

    return 0;
}