A function call in a for loop's conditional is practically C best practice. K&R do it on almost every page.

They usually only do it for builtins (e.g., strlen) and const functions, which makes this example a lot safer.

A bit suspicious, maybe? I was trying to suggest the unsigned issue without actually spelling it out, not anything to do with side effects.

I probably should have used sizeof, even though that doesn't make sense there.