Linked list in C

LinkedList.c

/*
 * LinkedList.c
 *
 *  Created on: 4 Nov 2015
 *      Author: Alex
 */

#include <stdlib.h>
#include <stdio.h>


struct node {
	int val;
	struct node* next;
};

int length(struct node* head){
	struct node* current = head;
	int count = 0;

	while(current != NULL){
		count++;
		current = current->next;
	}

	return count;
}

void push(struct node** headRef, int val){
	struct node* newNode = malloc(sizeof(struct node));

	newNode->val = val;
	newNode->next = *headRef;
	*headRef = newNode;
}

void addLast(struct node** headRef, int val){

	struct node* current = *headRef;
	struct node* newNode;

	newNode = malloc(sizeof(struct node));
	newNode->val = val;
	newNode->next = NULL;

	if(current == NULL){
		*headRef = newNode;
	}else{
		while(current->next != NULL){
			current = current->next;
		}
		current->next = newNode;
	}
}

void printList(struct node* head){
	struct node* current = head;

	while(current != NULL){
		printf("%i,",current->val);
		current = current->next;
	}
	printf("\n");

}

struct node* copyList(struct node* head){

	struct node* current = head;
	struct node* new = NULL;
	struct node* tail = NULL;

	while(current != NULL){

		if(new == NULL){
			new = malloc(sizeof(struct node));
			new->val = current->val;
			new->next = NULL;
			tail = new;
		}else{
			tail->next = malloc(sizeof(struct node));
			tail = tail->next;
			tail->val = current->val;
			tail->next = NULL;
		}

		current = current->next;
	}

	return new;
}

struct node* copyList2(struct node* head){

	struct node* current = head;
	struct node* new = NULL;
	struct node* tail = NULL;

	while(current != NULL){
		if(new == NULL){
			push(&new, current->val);
			tail = new;
		}else{
			push(&(tail->next),current->val);
			tail = tail->next;
		}
		current = current->next;
	}

	return new;
}

struct node* copyList3(struct node* head){
 //using dummy node;
	struct node* current = head;
	struct node* tail = NULL;
	struct node dummy;

	dummy.next = NULL;
	tail = &dummy;

	while(current != NULL){
		push(&(tail->next),current->val);
		tail = tail->next;
		current = current->next;
	}

	return dummy.next;
}

int main(){


	struct node* list = NULL;

	push(&list, 4);
	push(&list, 5);
	push(&list, 6);
	addLast(&list, 10);
	addLast(&list, 11);
	addLast(&list, 12);

	printList(list);
	printf("length of list: %i\n", length(list));

	struct node* copy = copyList3(list);

	printf("copy list: \n");
	printList(copy);

}