/*
  gcc -g nullPointer.c
  gdb a.out
  run
  print p
  backtrace
 */
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
  printf("%d\n", __LINE__);
  int *p = NULL;
  printf("%d\n", __LINE__);
  *p = 3;
  printf("%d\n", __LINE__);
  return 0;
}