Thread: Linked Lists

G'ah my c programming needs major improvement. I've created a function that reads information from files and then enters this information in a linked list.

What I've done is a bit of a mess as I'm not at all confident what I'm doing is correct, in fact I know its wrong. I'll give you the code I've written and then write down what i'm trying to achieve with it.

Code:

ListNode *read_vectorfiles(FileNames vectorFile)
{
	FILE *fptr;
	int vectorCount, i=0;
	ListNode *head=(ListNode *)malloc(sizeof(ListNode));
	ListNode *node=0;
	Colour *colour=colour_create();
	Vector *position=vector_create();

	/*Open the file*/
	fptr=fopen(vectorFile.fileName, "r");

	fscanf(fptr, "Vector Count: %d\n\n", &vectorCount);
	
	node=head;

	for(i=0; i<vectorCount; i++){
		fscanf(fptr, "position: %f %f %f %f", &position->x, &position->y, &position->z, &position->w);
		fscanf(fptr, "colour: %f %f %f %f\n", &colour->r, &colour->g, &colour->b);
		node->next=(ListNode *)malloc(sizeof(ListNode));
		node->next->colour=(Colour *)malloc(sizeof(Colour));
		node->next->vector=(Vector *)malloc(sizeof(Vector));
		node->next=vectorlist_setnode(position, colour);
		node=node->next;
	}

	printf("Here is one of the read colours apparently %.2f\n\n", head->next->colour->r);


	return(head);
}

I'm allocating a whole load of memory - is the allocation correct? and I'm doing this as it reads the relevant details and then I'm sending the newly read data off to a function to set the values.

The reason i have a node=head in there is because I want to return the head and using the node to loop through the linked list allows me to do that, but I think what I've done there is wrong also.

The structure of my ListNode:

Code:

typedef struct tagListNode{
	Vector *vector;
	Colour *colour;
	struct tagListNode *next;
}ListNode;

This is all a complete mess I know but any help is much appreciated.

Cheers

It looks ok to me but you don't need to cast malloc()

I always thought if you were mallocing a variable that you had created it needed to be cast?

http://faq.cprogramming.com/cgi-bin/...&id=1043284351

I don't think that you close the file, fptr.