C pointer pointer, and seg fault

Question

Below is my simple linked list in C. My question is in \"headRef = &newNode;\" which causes segmentation fault. Then I tried instead \"*headRef = newNode;\" which resolves the s

Answer 1

You have a fundamental misunderstanding of reference semantics via pointers. Here's the core example:

// Call site:
T x;
modify(&x);         // take address-of at the call site...

// Callee:
void modify(T * p)  // ... so the caller takes a pointer...
{
    *p = make_T();  // ... and dereferences it.
}

So: Caller takes address-of, callee dereferences the pointer and modifies the object.

In your code this means that you need to say *headRef = newNode; (in our fundamental example, you have T = struct node *). You have it the wrong way round!