Back in June I wrote about how to delete Ruby gems and presented a solution that involved a short script. Recently I went through another round of cleaning up Gems and discovered and even shorter method for deleting them.
for i in `gem list --no-versions`; do gem uninstall -aIx $i; done
This will ignore all default Gems errors. Simple and direct.
The flags specified with the gem uninstall, -aIx mean the command will remove all matching
versions (-a), will ignore dependency requirements (-I), and will remove executables without
needing confirmation (-x). You can read more about gem uninsall on the RubyGems
Guide.