reverse doubly linked list

void reverse(struct node **head_ref)

{

     struct node *temp = NULL; 

     struct node *current = *head_ref;

      

     /* swap next and prev for all nodes of

       doubly linked list */

     while (current !=  NULL)

     {

       temp = current->prev;

       current->prev = current->next;

       current->next = temp;             

       current = current->prev;

     }     

      

     /* Before changing head, check for the cases like empty

        list and list with only one node */

     if(temp != NULL )

        *head_ref = temp->prev;

}