Agreed. Looks useful. I am no command-line ninja and often struggle with the commands, so I can see myself using this. Having said that, I would not know something was dangerous till I executed it, which by then would be too late. Flagging something as dangerous is probably a good idea.

You allow users to click on the command and it turns into this text box. Is there a way to get a single click - copy this to clipboard option? It doesn't make that much of a difference to me, but I figured it would be a nice feature to have.

Good job, will look out for you on twitter