Ubuntu – Installing GruntJS on Ubuntu 13.04 does not run client (same for all NPM -g modules)

Okay here's probably an easy one for anyone familiar with Ubuntu.

I have installed NodeJS (v.0.10.10) and NPM. I ran:

sudo npm install -g grunt-cli

and

sudo npm install -g grunt

(in every combination)

but although everything seems to install successfully, i.e. I see in /usr/lib/node_modules the grunt-cli folder and I navigate to the bin, and see the grunt exe, when I try to type grunt, I don't get any errors, but just nothing except the next command line prompt.

BTW – I've tried installing jasmine-node globally as well with the same results.

I installed npm and nodejs from Chris Lea's PPA.