What are the most common naming conventions in C?

Question

What are the naming conventions commonly use in C? I know there are at least two:

1. GNU / linux / K&R with lower_case_functions
2. ? name ? with UpperC

Answer 1

Well firstly C doesn't have public/private/virtual functions. That's C++ and it has different conventions. In C typically you have:

• Constants in ALL_CAPS
• Underscores to delimit words in structs or function names, hardly ever do you see camel case in C;
• structs, typedefs, unions, members (of unions and structs) and enum values typically are in lower case (in my experience) rather than the C++/Java/C#/etc convention of making the first letter a capital but I guess it's possible in C too.

C++ is more complex. I've seen a real mix here. Camel case for class names or lowercase+underscores (camel case is more common in my experience). Structs are used rarely (and typically because a library requires them, otherwise you'd use classes).