[RegEx]

I experienced the same frustration. The exercise that gave me the "ah-ha!" moment I needed was prepending to a linked list via the head instead of the tail: You need to pass the address of `head` into the function so that the new head is reflected in the calling environment when you say `head = np`.

[unwind]

... or have the list operation return the new list head, which can make it way cleaner. See glib's list APIs, for instance.

[RegEx]

Well I was simply meeting exercise requirements, which aren't necessarily the most practical.