memory corruption

Question

i was running a small c program:

#include
int main()
{
char *p;
p = (char *)malloc(10);
free(p);
free(p);
free(p);
printf(\"\\npointer is freed!!\         


        

Answer 1

Just to add to the other answers, I'd like to note that if you set the pointer to NULL and then called free(), the behaviour wouldn't be undefined anymore. It's pretty much a no-op. However, if the pointer is freed and you call free() on it again before assigning the pointer to a different location (even NULL), you can't be sure of what happens. It could result in a core dump on some implementations and nothing would happen on some others.