valgrind lab – Developers Area

install valgrind
check the following code:

<span style="font-size: 14pt;">#include<stdio.h>
#include<stdlib.h>

void main(void)
{
	int i;
	int *p1,*p2,*p3;
	int *p = (int *)malloc(100);
	p--;
	printf("%d\n",*p);
	p1 = (int *)malloc(200);
	p1--;
	printf("%d\n",*p1);
	p2 = (int *)malloc(300);
	printf("%d\n",*p2);
	free((void*)p2);
	*p2=90;
}
</span>

<span style="font-size: 14pt;">#include<stdio.h>

#include<stdlib.h>

void main(void)

{

int i;

int *p1,*p2,*p3;

int *p = (int *)malloc(100);

p--;

printf("%d\n",*p);

p1 = (int *)malloc(200);

p1--;

printf("%d\n",*p1);

p2 = (int *)malloc(300);

printf("%d\n",*p2);

free((void*)p2);

*p2=90;

}

</span>