cli.rb

require 'optparse'

# options hash to store parsed results
options = {}
# initialize option parser
OptionParser.new do |opts|
  # provide banner with basic usage example
  opts.banner = "USAGE do awesome stuff"
  # our rule to parse
  opts.on("-m", "--magick", "This stores our magick value") do |v|
    options[:magick] = v
  end
end.parse!