I installed gulp(globally) and it looks like it worked because it ran this code:
├── tildify@0.2.0
├── interpret@0.3.5
├── pretty-hrtime@0.2.1
├── deprecated@0.0
Turns out that npm was installed in the wrong directory so I had to change the “npm config prefix” by running this code:
npm config set prefix /usr/local
Then I reinstalled gulp globally (with the -g param) and it worked properly.
This article is where I found the solution: http://webbb.be/blog/command-not-found-node-npm