Rack::App CLI example command decleration

rack_app_cli.rb

require 'rack/app'

class App < Rack::App
  
  cli do 
     
    command :test do
      
      description "it's a sample test cli command"
  
      option '-c', '--content [STRING]', 'add content to test file the following string' do |string|
        options[:append]= string
      end
  
      action do |file_path|
        options[:append] ||= 'default'
  
        $stdout.puts options[:append],file_path
      end
  
    end
    
  end 
  
end