/* Print the "hostent" information for every host whose name is
 * specified on the command line. (nach Stevens)
 */
#include <stdio.h>
#include <sys/types.h>
#include <netdb.h>       /* for struct hostent */
#include <sys/socket.h>  /* for AF-INET */
#include <netinet/in.h>  /* for struct in_addr */
#include <arpa/inet.h>   /* for inet_ntoa() */

void pr_inet(char **listptr, int length);

int main(int argc, char **argv)
  {
  char *ptr;
  struct hostent *hostptr;

  while (--argc > 0) 
    {
    ptr = *++argv;
    if ((hostptr = gethostbyname(ptr)) == NULL)
      {
      printf("gethostbyname error for host %s\n",ptr);
      continue;
      }
    printf ("official host name: %s\n", hostptr->h_name);
    /* go through the list of aliases */
    while ((ptr = *(hostptr->h_aliases)) != NULL)
      {
      printf("    alias: %s\n", ptr);
      hostptr->h_aliases++;
      }
    printf("    addr type = %d, addr length = %d\n",
           hostptr->h_addrtype, hostptr->h_length);
    switch (hostptr->h_addrtype) 
      {
      case AF_INET: pr_inet(hostptr->h_addr_list, hostptr->h_length);
                    break;
      default:      printf("unknown address type\n");
                    break;
      }
    }
  return 0;
  }
      
void pr_inet(char **listptr, int length)
/* Go through a list of internet addresses,
   printing each one in dotted-decimal notation. */
  {
  struct in_addr *ptr;
  while ( (ptr = (struct in_addr *) *listptr++) != NULL)
    printf (" Internet address: %s\n", inet_ntoa(*ptr));
  }