What I'm wanting to do is, whenever a weapon or armor's durability reaches zero, it gets removed from your inventory, and a "broken" (unrepairable) version of the same weapon/armor is added to your inventory. So, I think what I need is to be able to get the current and max durability of your currently equipped items, as well as what type they are. Afaik, neither of those things is possible with the vanilla game though. Do any of you know how I might go about doing that?

I just found getweapontype and getarmortype. Doesn't do quite what I wanted, but I could make them work if there's nothing else. Still can't detect their durability though.