[C] problem with free()

[Navimel]

Hi,

i have a list which is my p, this list could have lot of elements.

I use this code below to free the memory at the end of my program.

A strange things happen, at certain point i dont know why, the execution stop at the free(app);

I have this problem just on Windows! On linux every thing is fine

Does someone know what can cause this stop problem?

while(p!=NULL){
		app=p;
                free(app);
		p=p->next;


	}

thanks

[Duoas]

Does

while (p != NULL) {
  app = p;
  p = p->next;
  free( app );
  }

fix it?

[laserlight]

It looks like you used free(app) a little too early. It should probably be:

while(p!=NULL){
    app=p;
    p=p->next;
    free(app);
}

[Navimel]

thanks a lot i was going crazy

[vijay.yande]

may be freeing it reverse help

[code_carnage]

while(p!=NULL){
		app=p;
	                    free(app);
		p=p->next;


	}

Idea is when app=p; both are pointing to the same memory location.

and now you do free(app) hence memory pointed by app will be gone.
Since p also points to the same memory, hence memory pointed by p is also gone making it a dangling pointer and then you are trying to access the memory which no longer exists through the dangling pointer p.. Which lead to an UB and most likely a crash..