I'm rewriting a small MIT-licensed program in C, and I intend to copy a segment from it (though not verbatim) that prints usage information and such things. The programs are going to behave, for the most part, the same, but the implementations are going to be much different.

What is the best way to incorporate this code into my program, whether it's licensed under Apache 2, GPLv2/3, or under the MIT license?

My guess is that for the first two listed I'd just add the original authors name to the NOTICE file along with relevant information and paste the license header as a comment above the derived code, and for the latter I'd just add the original author's copyright statement above my own.