In order to uninstall all gems, you have to loop through all entries in
gem list with bash scripting. This method is very inconveninent. Thanks to Rubygems 2.1.0, you now could do it with one command.
Firstly, please make sure you upgrade your Rubygems to 2.1.0 or newer:
1 2 3
and in order to uninstall all gems:
That’s it folks!