Is there a Linux alternative for windows.h?

Question

I wonder how to access the linux API in a C++ , program

Answer 1

It really depends on what you are trying to do.

I would be looking at ncurses if you're looking to manipulate the console.

Answer 2

Linux has many headers. The main one is <unistd.h>, but here are many more.

Check /usr/include or the 2nd and 3rd sections of man.

Edit: an incomplete list can be found here: https://pubs.opengroup.org/onlinepubs/9699919799/idx/head.html