Doble connected spisoc

#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <stddef.h>

typedef struct node{
	int value;
	struct node *early;
	struct node *next;
} node;

typedef struct { //for easy keaping all list
	int size;
    node *head;
    node *tail;
}str_list;

void insert_first (str_list *list, int value){
	node *tmp = (node*) malloc(sizeof(node));
	tmp -> value = value;
	tmp -> next = list -> head;
	tmp -> early = NULL;
	if (list -> head) { //if not zero element in list
	    list -> head -> early = tmp;
	}

	if (list -> tail == NULL) {
 	   list -> tail = tmp;
	}
	list -> head = tmp;
	list -> size ++;
}

void inserting (str_list *list, int value, int key){
	node *tmp = (node*) malloc(sizeof(node));
	tmp -> value = value;
	int i = 1;
	node *iter = list -> head;

	while ((iter -> value != key) && (i < list -> size)){
		iter = iter -> next;
		i++;
	}

	if (iter -> value != key){
		printf ("-1\n");
		printf ("\n");
	}
	else {
		node *iter2 = iter;
		tmp -> early = iter;
		tmp -> next = iter -> next;
		iter -> next = tmp;
		if (iter2 -> next != NULL){
			iter2 = iter2 -> next;
			iter2 -> early = tmp;
		}
		else{
			list -> tail = tmp;
		}

		list -> size ++;
	}

}

int delete_first (str_list *list){
	if (list -> head != NULL){
		node *tmp = list -> head;
		list -> head = list -> head -> next;
		if (list -> head) { //it means that's not last elm
	        list -> head -> early = NULL;
	    }
		if (tmp == list -> tail) {
	        list -> tail = NULL;
	    }

		free (tmp);
		list -> size --;
		return 1;
	}
	else{
		printf ("UNDERFLOW\n"); //u want delete frow empty stack
		return -1;
	}
}


int delet (str_list *list, int key){
	if (list -> head != NULL){
		node *tmp;
		int i = 1;
		node *iter = list -> head;

		while ((iter -> value != key) && (i < list -> size)){
			iter = iter -> next;
			i++;
		}

		if (iter -> value != key){
			return -1;
		}
		else {
			if (iter == list -> head){
				int del;
				del = delete_first (list);
				return del;
			}
			else{
               	tmp = iter;
				node *iter2 = iter -> next;
				iter = iter -> early;
				iter -> next = iter2;
				if (iter2 != NULL){
					iter2 -> early = iter;
				}
				else{
					list -> tail = iter;
				}
				free (tmp);
				list -> size --;
				}
				return 1;
			}
	}
	else{
		printf ("UNDERFLOW\n"); //u want delete frow empty stack
		return -1;
	}

}

void search_ (str_list *list, int key){
	node *iter = list -> head;
	int i = 1;
	while ((iter -> value != key) && (i < list -> size)){
		iter = iter -> next;
		i++;
	}
	if (iter -> value != key){
		printf ("not found\n\n");
	}
	else {
		printf ("element found with index number: %d \n\n", i);
	}
}


void output_ (str_list *list){
	if (list -> size == 1)
		printf ("1 element: ");
	else
		printf ("%d elemens: ", list -> size);
	node *iter = list -> head;
	if (iter != NULL){
		while (iter != NULL){
			printf("%d ", iter->value);
			iter = iter -> next;
		}
	}
	else{
		printf ("empty stac");
    }
	printf("\n");
	printf("\n");
}

int main (void){

	str_list *list = (str_list*) malloc(sizeof(str_list));
    list->size = 0;
    list->head = list->tail = NULL;

	FILE *mf;
	printf ("opening file :");
	mf = fopen ("C:\\Users\\Anna\\Documents\\ci\\input_double.dat","r+");
	if (mf == NULL)
		printf ("error\n");
	else printf ("done\n");
	char action [12];
	char insert[] = "INSERT";
	char delete[] = "DELETE";
	char search[] = "SEARCH";
	int value, key;

	while (1){
		if(fscanf(mf, "%s %d %d", action, &key, &value)==EOF) break;
		puts (action);

		int res = strcmp (action, insert);
		if (res == 0){
			printf ("%d %d\n", key, value);
			if (key == 0){
				insert_first (list, value);
				output_(list);
			}
			else{
				inserting (list, value, key); //key is elem after which we insert
				output_(list);
			}
		}
		res = strcmp (action, delete);
		if (res == 0){
			printf ("%d\n", key);
			int del;
			del = delet (list, key);
			printf ("result: %d\n", del);
			output_(list);
		}

		res = strcmp (action, search);
		if (res == 0){
			printf ("%d\n", key);
			search_ (list, key);
		}
    }

	fclose (mf);
	printf ("file closed\n");
	return 0;
}