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

int main ()
{
  // Declare a pointer to an int.
  int *p;

  // Print the initial value of the pointer:
  printf ("Initial value of pointer: %p\n", p);    // Prints 0 (C99)

  printf ("The number of bytes needed by an integer: %d\n", sizeof(int));

  // Get the space from malloc:
  p = (int*) malloc (sizeof(int));

  // Print the address of the memory block returned by malloc:
  printf ("Current pointer: %p\n", p);

  // Assign a value and print:
  *p = 5;
  printf ("Int value: %d\n", *p);

  // Free the memory when done:
  free (p);

}