hostent query

[JaybOt]

Hi all,

Im using gethostbyname() to resolve a domain name or IP but i am having trouble trying to return readable data from the member function h_addr_list[0]. Here is a code snippit of what im trying to do ..

struct hostent *he
.
if((he=gethostbyname(host))==NULL) {
exit(-1); /*exit on failue*/
}

my problem is in trying to print the data held in he->h_addr_list[0]. I think im wright in saying that _addr_list[0] is returned in network byte order so no coversion is needed using htonl, i have also tried using inet_ntoa(*((struct in_addr *)he->h_addr_list[0])) with no success.

Can someone please tel me where im going wrong here, and possably point me in the wright direction?

Thanks in advance,
J@yb0t

Always know what you say, but don't always say what you know!

 

[itsgsd]

Without seeing more of your code I'm not sure what is going on. Here's a snippet extracted/modified from one of my working programs that should work. Also, inet_ntoa has been deprecated in favor of inet_ntop.

#include <stdio.h>
#include <netdb.h>
#include <netdb.h>

int main(int argc, char *argv[])
{
  struct hostent *hostPtr = NULL;
  char *remoteHost = NULL;
  char str[INET6_ADDRSTRLEN];
  char **p;

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

  remoteHost = argv[1];

  hostPtr = gethostbyname(remoteHost);
  if (NULL == hostPtr)
  {
    perror("Error resolving server address");
    return 1;
  }

  printf("%s\n",hostPtr->h_name);
  p = hostPtr->h_addr_list;
  for ( ; *p != NULL; p++) {
    printf("address: %s\n",inet_ntop(hostPtr->h_addrtype,p,str,sizeof(str)));
    printf("         %s\n",str);
  }
}

Hope this helps.

 

[JaybOt]

Thanks itsqsd,

Havent had a chance to modify my code and test this yet, but ill post again when i do and let you know how i get on!

I cant see that i'll have any problems though ..

regards,

J@yb0t

Always know what you say, but don't always say what you know!