Is it possible to keep original scrollback buffer intact?

[sewbacca]

I'd like to write a shell like application with autocompletion, so I will only ever have write to the buffer downwards the terminal, meaning I won't be needing to reread the scrollback buffer. Is it possible to keep the original scrollback buffer intact, while still capturing i/o events?
Also to be able to do something meaningful with it, I would probably benefit from an get_cursor function or relative cursor jumps.

[adsr]

If I understand correctly, you're interested functionality similar to readline. termbox doesn't support this, and I think it's too different of a use-case to include in the API. A built-in assumption of termbox is that you'll be controlling the contents of the entire terminal. (You can of course use readline in conjunction with termbox, but that won't help you if you don't want to manage scrollback yourself.)

I have thought about writing a readline alternative inspired by termbox. It could benefit from the the same terminfo-parsing and built-in defaults that termbox uses. The API would look different though.

For now I would recommend using something like readline, linenoise, or libedit, or using termbox and managing scrollback yourself.