ubuntu install node/npm

1. sudo apt-get install nodejs

2. sudo apt-get install npm

3. check version

   node -v

   npm -v

4. get/set npm mirror website

   npm config get registry

   npm config set registry https://registry.npm./

5. clean npm cache

   npm cache clean -f

6. install n module

   npm install -g n    # n be used to mange node

7. upgrade newest node

   n stable

8. uninstall

   sudo apt-get remove --purge npm

   sudo apt-get remove --purge nodejs

   sudo apt-get remove --purge nodejs-legacy

   sudo apt-get autoremove

   rm -r /tmp/npm*