Quickly find if you're running the latest rbenv

latest_ruby.rb

#!/usr/bin/env ruby

def get_lines(output)
  output.lines.map(&:chomp).map(&:strip)
end

available = get_lines(`rbenv install -l`).select { |v| v.match(/^[\d\.]+$/) }
installed = get_lines(`rbenv versions`)

puts
puts "Installed"
puts "="*40
puts installed

puts
puts "Last 3 Stable"
puts "="*40
puts available.last(3)