Question: Is __FILE__ for getting the currently running file an official feature?

[kyleplo]

I've been looking for a while for a way to get the currently running file, and came across __FILE__ which seems to do exactly what I want. However, I don't see it documented anywhere. Before I publish any code using it, I'd like to make sure that __FILE__ is an official feature that can be used in production code.
If not, is there another way to do what I want?

[gfwilliams]

Yes, this is definitely an official feature that you can rely on. Good point about the docs - I'll add something now.