[C] problem with free()

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 :ehh:

Does someone know what can cause this stop problem?

Code:

---

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


        }

---

thanks

Does

Code:

---

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

---

fix it?

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

Code:

---

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

---

thanks a lot i was going crazy :wave:

may be freeing it reverse help

Quote:

---

Originally Posted by Navimel

Code:

---

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..