#include <stdio.h>
#include <memory.h>
#include <netdb.h>
#include <arpa/inet.h>

extern int h_errno;

int main(int argc, char **argv) {
  struct in_addr addr;
  unsigned char a[] = { 255, 0, 0, 0 };
  struct hostent *hep;
  int errn;

  memcpy(&addr, a, 4);
  hep = gethostbyaddr((void *) &addr, sizeof addr, AF_INET);
  printf("hep=%p h_errno=%d\n", hep, h_errno);
}