basic implementation of linkedlist in c

linkedlist.c

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

// const
#define AtBeginning 1
#define AtEnd 0

struct Node
{
	int data;
	struct Node *next;
};

//get a random number
int once = 1;
int randomValue(){
	if (once){
		srand(time(NULL));   // should only be called once
		once = !once;
	}
    return rand();  
}


struct Node* creatNewNode(){
	return (struct Node*) malloc(sizeof(struct Node));
}

void printList(struct Node* list){
	while(list != NULL){
		printf("%d\n", list->data);
		list = list->next;
	}
}

void insertAtBeginning(struct Node** head, int data){
	struct Node* new_node = creatNewNode();
    new_node->data = data;

    /* Make next of new node as head */
    new_node->next = (*head);
    /* move the head to point to the new node */
    (*head)    = new_node;
}

void insertAtEnd(struct Node** head, int data){
	struct Node* new_node = creatNewNode();
	new_node->data = data;

	struct Node* head_ref = *head;

	/*new_node is going to be the last node,
	so make next of it as NULL*/
	new_node->next = NULL;

	//what if the list is empty
	if (head_ref == NULL)
	{
		//we are alone so we are the head
		*head = new_node;
	}

	// take out the last one
	while(head_ref->next !=NULL) head_ref = head_ref->next;

	//grab your seat
	head_ref->next = new_node;

}

void insertAfter(struct Node** node, int data, int where){

	struct Node* node_ref = *node;
	

	// what if the given is the last node
	if (node == NULL)
	{
		// insertAtEnd(node, data);
		return;
	}

	struct Node* new_node = creatNewNode();
	new_node->data = data;

    // Make next of new node as next of prev node
	new_node->next = node_ref->next;

	//grab the seat
	node_ref->next = new_node;
}

void insert(int where, struct Node** head, int data){
    // 1 - Insert at Beginning
	if (where == AtBeginning) insertAtBeginning(head, data);
	 // 0 - Insert at End
	if (where == AtEnd) insertAtEnd(head, data);

	//else inset at the given positoin
}


int main()
{
	struct Node* head = creatNewNode();
	struct Node* second = creatNewNode();
	
	head->data = 1;
	head->next = second;

	second->data = 2;
	second->next = NULL;
	
	printf("original\n");
	printList(head);

	insert(AtBeginning, &head, randomValue());

	printf("AtBeginning\n");
	printList(head);


	insert(AtEnd, &head, randomValue());

	printf("AtEnd\n");
	printList(head);
	
	return 0;
}