title: IRB analogue of python -i
body: <p>I want to use IRB to run a script then give me an interactive prompt. I do this with <code>python -i xy.py</code> in Python, however <code>irb xy.rb</code> exits after execution.</p>
  
  <pre><code>&gt; python --help
  
  -i    When a script is passed as first argument or the -c option is
        used, enter interactive mode after executing the script or the
        command
  </code></pre>