This project is both my personal LEGO inventory and the software that powers it. It is very much a work in progress, but if you are looking for a simple LEGO inventory manager with a CLI interface, this might be a good starting point.
This is likely only useful to experienced LEGO enthusiasts who happen to also be software developers. There's no graphical interface, so if you regularly need to look up part names or numbers, this will likely be a very slow tool for you. It is very fast once you have a lot of things memorized, though.