My primary use of Google Code search was, searching for this rare function (like a POSIX one) whose man page I can't understand and is largely undocumented else

My primary use of Google Code search was, searching for this rare function (like a POSIX one) whose man page I can't understand and is largely undocumented elsewhere. I would often try to understand how other projects are using this function via internet-wide code search. :D While Github is great, I think it still hosts only a small fraction of all the code that is public.