/*
PROGRAM  : nullptr.c
PURPOSE  : to check if your runtime environment reports null pointers. 
UNIX COMP: gcc -o nullptr nullptr.c
PC COMP  : TURBO C++ (tcc) or Borland
TEST     : nullptr
*/

#include <stdio.h>
#include <stdlib.h>

typedef struct node *node_ptr;
struct node {
  int element;
  node_ptr next;
};

int main(int argc, char *argv[]) {
  node_ptr p = NULL;
  printf("TEST PROGRAM: nullptr.c\n");
  printf("PURPOSE: to check if your runtime environment reports null pointers.\n");
  printf("BEFORE a null pointer reference.\n");
  if (p->next)
    p = p->next;
  printf("AFTER a null pointer reference.");
  printf("Did your runtime environment report on the null pointer reference?\n");
  return 0;
}