...if I only Node...

[code]
typedef struct Supreme
Supreme *head;
Supreme *prev;
char *stringData;
Supreme *next;
Supreme *tail;



CreateAddSupremeNode (Supreme *head)
Supreme s = (Supreme *)malloc (sizeof(Supreme));
if(head == NULL)
{ head = s;
return s; }
Supreme x;
for(x = head; x != NULL; x = x->next)

;
x->next = s;
return s;

???This Crashes My System....

Code:

---

Supreme *CreateAddSupremeNode( Supreme **head )
{
    Supreme s = malloc( sizeof( Supreme ) );

    if (*head == NULL)
    {
        *head = s;
    }
    else
    {
        Supreme x;

        for( x=*head; x && x->next; x = x->next );
        x->next = s;
    }
    return s;
}

---

In both cases you were trying to use null pointers. If head was null, you cannot assign it the value of s. This:

if( node->next == NULL ) node->next = s;

Is not the same as:

if( head == NULL ) head = s;

The second problem was that your loop would make sure that 'x' was null, then you'd try assigning 'x->next' a value, and since 'x' was already null, BadThings(TM) happened.

Quzah.

Ok but why **head?

Won't *head work?

Consider a call to CreateAddSupremeNode...

Code:

---

int main ()
{
 Supreme * head = NULL; // The list is empty.
 CreateAddSupremeNode (head); // This is bad...
 // Now the list is not empty, so the value of head is not NULL.
 //  BUT that means changing the value of a passed variable,
 //  and the only way to do that is to pass a reference to the
 //  variable, which would be...
 CreateAddSupremeNode (&head); // This is correct way to
 // change value of head.
 return 0;
}

---

So, since head is a Supreme *, &head is gonna be a Supreme **, and instead of changing the value of head in your function, you'll have to change the value of *head.

Thanks, guys.