That is correct, yes. You can limit the scope of a function to a single file using the static keyword; otherwise all functions are in the same global namespace

That is correct, yes. You can limit the scope of a function to a single file using the static keyword; otherwise all functions are in the same global namespace for static linking. In practice, this is not a big limitation by itself. Although C has function pointers, it's not a functional programming language -- there are no closures, and you can't create new functions at run-time under any circumstances. (Not within the language itself, anyway. You'd need to embed a compiler, or at least a minimal code generator.) On Harvard-architecture systems like microcontrollers, code and data may be in different memories (ROM vs. RAM) with different access permissions, and some platforms even put them in entirely separate address spaces.