How to create a copy of a linked list? Write a C program to create a copy of a linked list.

copy_linked_lists(struct node *q, struct node **s) {
    if(q!=NULL)
    {
        *s=malloc(sizeof(struct node));
        (*s)->data=q->data;
        (*s)->link=NULL;
        copy_linked_list(q->link, &((*s)->link));
    } }

Ref: http://technical-interview.com