Simple WEBrick Command. (My ruby version: ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-darwin12.2.0])

webrick.rb

#!/usr/bin/env ruby

require 'webrick'
require 'optparse'
 
port = 8000
root = '.'
 
OptionParser.new do |opt|
  opt.on('-p', '--port PORT', "default: #{port}") { |v| port = v }
  opt.on('-d', '--directory DOCUMENT_ROOT', "default: #{root}") { |v| root = v }
  opt.parse!
end
 
server = WEBrick::HTTPServer.new :Port => port, :DocumentRoot => root
trap 'INT' do server.shutdown end
server.start