title: Duplicating stdout to stderr
body: <p>I'd like to have the stdout of a command replicated to stderr as well under bash. Something like:</p>
  
  <pre><code>$ echo "FooBar" (...)
  FooBar
  FooBar
  $
  </code></pre>
  
  <p>where (...) is the redirection expression. Is that possible?</p>