title: Capture stdout and stderr into different variables
body: <p>Is it possible to store or capture stdout and stderr in <em>different variables</em>, without using a temp file?  Right now I do this to get stdout in <code>out</code> and stderr in <code>err</code> when running <code>some_command</code>, but I'd
  like to avoid the temp file.</p>
  <pre><code>error_file=$(mktemp)
  out=$(some_command 2&gt;$error_file)
  err=$(&lt; $error_file)
  rm $error_file
  </code></pre>