Thread: printing from void pointer

Code:

int main()
{
	List* newList= lst_new();
	names* nama;
	char* data;
	int x=1;
	
	while(x == 1)
	{
	nama = names_new();
	lst_add(newList,nama);
	
	for( data = lst_first(newList);
					data != NULL;
						data = lst_next(newList))	 
		printf("-- %s --\n",(char*)data);  /* prints (giberish)*/
		printf("\n");
	
	
	names_delete(nama);
	
	printf("x = ?? :");
	scanf("%d",&x);
	
	while(getchar() != '\n');
	}
	return 0;
}

i cant seem to be able to print a string, can any one tell me where im going wrong.. the functions lst_next() lst_first() return void*.

yea, its a linked list attempt

Originally Posted by laserlight

Why do they return void*?

"If so, then you should dereference that pointer to get the data pointer, and cast that data pointer to char*." , thats actually what the functions do. the data pointer is a void pointer hence the return type

Code:

/*
 * Position iterator to head of list and return its data.
 */
void *lst_first(List *lst)
{
    lst->iterator = lst->head;
    if(lst->iterator != NULL)
        return nd_getData(lst->iterator);
    else
        return NULL;
}


/*
 * Position iterator to next node in list and return its data.
 */
void *lst_next(List *lst)
{
    if(lst->iterator != NULL)
    {
        lst->iterator = nd_getNext(lst->iterator);
        if(lst->iterator != NULL)
            return nd_getData(lst->iterator);
    }
    return NULL;
}

and the list

Code:

/* Linked list data */
typedef struct
{
    Node *head; /* First element in list */
    Node *tail; /* last element in list */
    Node *iterator; /* Used to iterate through list */
    int size;   /* number of elements currently in list */
} List;

alright thanks,will look into it. for now sleep whispers sweet sounds in my ear

Code:

return nd_getData(lst->iterator);

What is getdata returning?

Thanks for the help. problem was with some of my system settings