How to write full-screen Linux console app/script?

Question

I'm having a hard time even googling this, because I don't know the right keywords. Some command-line apps (such as vi and less) take over the whole console screen and present an interactive interface to the user. Upon exiting such an app, the screen is returned to the state it was in before the app was launched. I want to write a program that behaves in this fashion, but again, I don't even know what this is called, so I can't find any documentation for how it's accomplished.

So, my question is threefold:

1. What keywords can I use to find documentation on this?
2. If you are so inclined, links to such documentation would be helpful.
3. Lastly, can I accomplish this in a scripting language like Ruby, or even bash? I have no problem with C, but the environment I work in is more amenable to interpreted languages.

Answer 1

As said in some comments, you are looking for ncurses. The Linux Documentation Project have a very good HOWTO on ncurses for C that I used myself to start on it

https://tldp.org/HOWTO/NCURSES-Programming-HOWTO/

Answer 2

The feature you are describing is the alternate screen buffer. I think that [N]Curses will enable this by default. There are certainly curses bindings for Ruby, Python, and other scripting languages.