Programming?

I’m new to C and C++ programming and I’ve learn them through books and online tutorials. But all the tutorials I’ve encountered only provide lessons that teaches us how to take inputs from the keyboard. Is there anyway to write a program that takes input from other I/O interfaces such as serial ports, parallel ports or usb? What are the knowledge that I need and the steps on learning that? I would be very grateful if anyone could provide me some links of the tutorials. Thank you very much.

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