httpd.rb

# -*- mode: ruby; coding: utf-8-unix -*-

require 'time'
require 'webrick'

server = WEBrick::HTTPServer.new(:BindAddress => '0.0.0.0',
                                 :Port => 3000,
                                 :DocumentRoot => ARGV.shift || Dir::pwd)
server.mount("/",
             WEBrick::HTTPServlet::FileHandler,
             Dir::pwd,
             :FancyIndexing => true,
             :FileCallback => Proc.new {|req, res|
               res['Cache-Control'] = 'no-cache, no-store, must-revalidate'
               res['Expires']       = Time.at(0).httpdate
             })

trap("INT") do
  server.shutdown
end
server.start