rubygems: uninstall some gems

I just discovored a way to uninstall only the gems that match a pattern (via https://coderwall.com/p/lpqmjq )

gem list [OPTIONAL PATTERN] --no-version | xargs gem uninstall -ax

for example

gem list hobo --no-version | xargs gem uninstall -ax

removes all 'hobo'

Successfully uninstalled hobo_jquery_ui-2.0.1
Successfully uninstalled hobo_clean_admin-2.0.1
Successfully uninstalled hobo_clean-2.0.1
Successfully uninstalled hobo_bootstrap_ui-2.0.1
Successfully uninstalled hobo_bootstrap-2.0.1
Successfully uninstalled hobo_jquery-2.0.1
Successfully uninstalled hobo_rapid-2.0.1
Removing hobo
Successfully uninstalled hobo-2.0.1
Removing hobofields
Successfully uninstalled hobo_fields-2.0.1