I wonder who has copyright over the file API (e.g. open(), close(), etc.). Since filesystems are written by implementing this common API, I guess they'd all be

I wonder who has copyright over the file API (e.g. open(), close(), etc.). Since filesystems are written by implementing this common API, I guess they'd all be infringing someone's copyright. Also language interpreters and standard libraries that wrap those OS facilities to make them available in their language. Linux PAM modules are built by implementing an API defined by PAM. Language wrappers which allow us to use libraries written in different languages would all be violating copyright too, I guess. No more using GTK in a language different from C, for example. How far does this go?