title: Persisting an environment variable through Ruby
body: <p>I am trying to set my DOS environment variable in Ruby, and have it persist after the script exits. For example, if I want a ruby script <code>set_abc_env.rb</code> to set environment variable 'ABC' to 'blah', I expect to run the following:</p>
  
  <pre><code>C:&gt; echo %ABC%
  C:&gt; set_abc_env.rb
  C:&gt; echo %ABC% blah
  </code></pre>
  
  <p>How do I do this?</p>