#include <stdio.h>
#include <errno.h>
#include <netdb.h>      /* 4 gethostbyname, hostent structure */
#include <unistd.h>     /* 4 exit */
#include <netinet/in.h> /* 4 ntohn */

int main(int argc, char *argv[])
{
     int i,j;
     struct hostent *he;

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

     if ((he = gethostbyname(argv[1])) == NULL) 
     {  
          fprintf(stderr, "gethostbyname error\n");
          return 1;
     }

     /* host info: */
     printf("\nHost name: %s", he->h_name);
     printf("\nAliases:");
     for(i=0;he->h_aliases[i] != NULL;++i)
          printf("\n%d. %s", i+1, he->h_aliases[i]);
     if(he->h_addrtype == AF_INET)
          printf("\nAddres type: IPv4");
     if(he->h_addrtype == AF_INET6)
          printf("\nAddres type: IPv6");
     printf("\nAddress length: %d bytes", he->h_length);
     printf("\nAddresses:");
     for(j=0;j<he->h_length;++j)
     {
          printf("%d", (uint8_t)he->h_addr[j]);
          if(j < (he->h_length-1))
               printf(".");
     }
     printf("\n");

     return 0;
}