/* Using malloc() to determine free memory.*/

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

/* Definition of a structure that is
   1024 bytes (1 kilobyte) in size.) */

struct kilo {
	struct kilo *next;
	char dummy[1022];
};

int FreeMem(void);

main()
{

printf("\nYou have %d kilobytes free.", FreeMem());
return(0);
}

int FreeMem(void)
{
/*Returns the number of kilobytes (1024 bytes)
  of free memory. */

int counter;
struct kilo *head, *current, *nextone;

current = head = (struct kilo*) malloc(sizeof(struct kilo));

if (head == NULL)
    return 0;       /*No memory available.*/

counter = 0;
do
	{
	counter++;
	current->next = (struct kilo*) malloc(sizeof(struct kilo));
	current = current->next;
	} while (current != NULL);

/* Now counter holds the number of type kilo
	structures we were able to allocate. We
	must free them all before returning. */

current = head;

do
	{
	nextone = current->next;
	free(current);
	current = nextone;
	} while (nextone != NULL);

return counter;
}