I am planning on making a command shell game, and I want to know what the best way to provide a shell environment is for this.
I would like to be able to provide most of the standard utilities most terminal-users would expect from a terminal, such as grep, awk, sed, or man, but I also need to be able to customize and modify some of it (in particular ssh, all network interfacing, and a custom package manager) to be able to provide the intended gameplay.
In particular, I need to be able to display images in the terminal, e.g. via fbi, although there is no need to be able to use a full graphical environment - no X.
I've considered various computer emulators such as v86.js or jslinux. These could be customized by providing a disk image, and work exactly like real computers - I would just need to modify the disk image to get it to work the way I want. Doing this approach, I would certainly learn a lot about the inner workings of linux, but it would take a lot of time to do this.
Another option would be to implement my own console to do this. This might be simpler to do, but I don't think I would be able to provide as authentic an experience this way.
What would be the best (easiest/simplest) way to create/customize a command shell for this purpose?
