LOL IT'S C TIME

Hi /prog/, I have some experience with C, but I don't know how to do much except take text input, save variables, calculate, and print text out. What should I read to learn to do things like display graphics, save/load files, send/receive data using ports, et cetera?

It's not like there are cases when you can use both any of them in the same place, so why not have only .?
Write more C.