The code is written in python and is very easy to use. It can be found here https://github.com/dmelo/vsnm .
I'm very angry about the way NetworkManager manages my network. Not because it uses graphical interface. But because when I want to change something by command line, there comes NetworkManager minutes/seconds afterwards to creep everything. I find it very hard to conciliate NetworkManager with command line management.
So I've created vsnm. For now, it only supports wifi (WPA/WPA2 and WEP) which, I believe, are the most critical to have.
Have fun ;)