As for CLI, there is a CLI tool I've used on Raspberry Pi. I setup a Pi that, when booted up, would pull updated image files out of Dropbox and apply them to whatever radio was plugged in (sort of a mobile updater). But, the CLI tool only works to upload/download to/from the radio and one-at-a-time memory changes. You'd still want to do the majority of your settings/channel/memory edits in a GUI. 
CLI Tool: https://github.com/b3n4kh/chirp

-Tycen