Formatters
RuboCop comes with a set of different formatters that let you control how the results are presented.
If you want to output the result in machine readable JSON;
rubocop --format json --out results.json
The rubocop-sketchup
gem provides a custom formatter designed for SketchUp related cops. It explains which cops to focus your attention on.
rubocop -f extension_review -o report.html
See RuboCop's documentation for more examples.