Default bin file for a ruby gem

default-rubygems-bin-file.rb

#!/usr/bin/env ruby

require File.join(File.dirname(__FILE__), *%w".. lib mygem")
require 'optparse'

options = {
  :help => false,
  :flag => false,
  :mandatory => nil
}

optparse = OptionParser.new do|opts|
  opts.on( '-h', '--help', 'Display help screen' ) do
    options[:help] = true
  end
  
  opts.on( '-f', '--flag', 'Simple flag') do
    options[:flag] = true
  end
  
  opts.on( '-m', '--mandatory', 'Mandatory argument') do |mandatory|
    options[:mandatory] = mandatory
  end
end

optparse.parse!

command = ARGV[0]
case command
  when "sub_command"
    #do sub command
  else
    puts %Q{
      mygem is a command line application
      
      Usage:
      mygem sub_command -f -m "this is mandatory"
      
      Options:
        -h, --help - Display the help screen
        -f, --flag - This flag toggles functionality
                     and can be used without a parameter
        -m, --mandatory - When this option is used, there is a madatory argument.
                          You should give an example: mygem -m "Some string"
    }
  end