How to make the view of a UIViewController to stick to the bottom of it's superview?

Question

Programmatically, and not with using xib files? UIView's autoresizingMask is not really the right thing, I think. Since it's not about resizing but laying out. I couldn't find layout masks. But Interface Builder seems to allow to attach a view to top, left, right, center or bottom. So there must be a mechanism.