#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <errno.h>
#include <unistd.h>

int main()
{
  int s, e;
  struct sockaddr_in ss;
  socklen_t len;

  s = socket(AF_INET, SOCK_STREAM, 0);
  len = sizeof(ss);
  e = getpeername(s, (struct sockaddr *)&ss, &len);
  printf("%d, %d, %d vs %d\n", s, e, errno, ENOTCONN);

  close(s);

  return 0;
}