Uninstall all installed gems, in OSX?

Question

There are instances where I would like to revert and uninstall all previous gem installations.

For instance, I needed to assist a friend migrate their rails developm

Answer 1

Rubygems >= 2.1.0

gem uninstall -aIx

If Terminal returns below error

ERROR:  While executing gem ... (Gem::FilePermissionError)
You don't have write permissions for the /Library/Ruby/Gems/2.0.0 directory.

Then write above command as below

sudo gem uninstall -aIx

And enter your mac os account password Done!!