heapcheck()             Check the Heap

 #include   <alloc.h>

 int heapcheck(void);

        This function walks through the heap, checking all block's
        pointers, size, and other features. In the large and huge models,
        heapcheck() becomes farheapcheck(). Possible returns:

                _HEAPOK         Heap is alright.
                _HEAPEMPTY      Heap is empty.
                _HEAPCORRUPT    Heap has been corrupted.

       Returns:     Greater than zero for success; negative otherwise.

   -------------------------------- Example ---------------------------------

 #include <stdio.h>
 #include <alloc.h>

 int main(void)

    if(heapcheck() == _HEAPCORRUPT)
       printf("Heap has problems.\n");
    return 0;