Silly little webserver

config.ru

# If you have ruby installed, you can use this file to run a basic web server
# and avoid silly cross-site forgery issues when doing your assignments.
#
# * Install ruby, if you haven't already
#     Macs come with ruby, so just open up a terminal and type: ruby -v
#     and press Return (or Enter or whatever).  If you get a response,
#     you have ruby already!  Move to the next step.  If not, consult Google.
#
#     Windows users can easily install ruby, just check out http://rubyinstaller.org/
#     When you're done installing, open up a command prompt (or powershell) and
#     type: ruby -v
#     and press Enter.  If you get a response, you have ruby!  Move to the next step.
#
# * From the command line (powershell, or cmd, or terminal), run:
#     gem install rack --no-rdoc --no-ri
#
# * Put this file in the same place as your `.html` file you want to play with.
#
# * From the command line, run the following command:
#     rackup config.ru
#
# Then you should have a running webserver.
#
# Now, open your browser at:
#    http://localhost:9292
#
# You should see a list of files from the directory where you started the webserver.
# If you haven't put your assignment into this directory yet, do so now, and refresh
# the page.  Now click on the file and you should see your assignment in all of its
# assigned glory.
#
# Enjoy!

# Here, we set `@root` to the directory this file resides in.
@root = File.expand_path(File.dirname(__FILE__))

# `run` is a Rack command, so when you run `rackup` from the command line,
# it looks for this `run` and starts up your web server.
run Proc.new { |env|
  # Extract the requested path from the request
  path = Rack::Utils.unescape(env['PATH_INFO'])

  index_file = @root + "/index.html"

  if File.exists?(index_file)
    if RUBY_VERSION < "1.9"
      [200, {'Content-Type' => 'text/html'}, File.read(index_file)]
    else
      [200, {'Content-Type' => 'text/html'}, [File.read(index_file)]]
    end
  else
    puts 'Index file does not exist, displaying directory tree.'
    Rack::Directory.new(@root).call(env)
  end
}

To save this file, click on the little <> in the top-right corner of the file's box and save that page where your assignment files will be. You can always move the file later if you "miss" the right directory. : )