C: Header Cell/Node in a Double Circularly Linkeded List

Hey guys!

I need some assistance in creating my header node or cell in a double circularly linked list. I have come up with the single linked list header node:

Code:

list_ptr createHeader (void){
 list_ptr L;
 L = (list_ptr) malloc(sizeof(list));
 L->next = NULL;
 return L;
}

However, I'm having difficulty in coding the header previous, which in fact would instantly point to the last node in my double circularly linked list. How do I go about adding that code to my createHeader function?

Is it as simple as stating the following:

Code:

L->prev = NULL;

Am I missing something?

Thanks again!
Regards,
Jose

 

Hey shabbir!

Thanks for the prompt reply. I am not really understanding your reply. How do we go about implementing that in my createHeader function?

Do you meant it will be assigned automatically?

Code:

L->prev=L;

Is that what you mean?

Thank you for your time,
Jose