require 'optparse' parser = OptionParser.new def xxx_handler(value) p ['Handler method for -xxx called with value:', value] end parser.on('--xxx', 'Option with no argument', method(:xxx_handler)) def yyy_handler(value) p ['Handler method for -yyy called with value:', value] end parser.on('--yyy YYY', 'Option with required argument', method(:yyy_handler)) parser.parse!