title: Running Sinatra on port 80
body: <p>I installed Sinatra and it works but it uses port 4567 by default. I want it to run on port 80.</p>
  
  <p>In an effort to get it to work on port 80, I tried this:</p>
  
  <pre><code>require 'rubygems'
  require 'rack/handler/webrick'
  require 'sinatra'
  
  Sinatra::Application.default_options.merge!(
    :run =&gt; false,
    :env =&gt; :production,
    :port =&gt; 80
  )
  
  get '/' do
    "Hello World"
  end
  </code></pre>
  
  <p>But I get this error:</p>
  
  <pre><code>$ ruby -rubygems index.rb
  index.rb:5:in `&lt;main&gt;': undefined method `default_options' for Sinatra::Application:Class (NoMethodError)
  </code></pre>
  
  <p>Any idea what's going on?</p>