title: ack: Excluding only one directory but keeping all others with the same name
body: <p>My folder structure looks like this:</p>
  
  <pre><code>/app
  /app/data
  ...
  /app/secondary
  /app/secondary/data
  </code></pre>
  
  <p>I want to recursively search <code>/app</code>, including <code>/app/data</code>. I do not want to search <code>/app/secondary/data</code> however. This what I have so far:</p>
  
  <pre><code>ack --ignore-dir=data searchtext
  ack --ignore-dir=secondary/data searchtext
  </code></pre>
  
  <p>The first command is ignoring both directories and the second one is ignoring neither of them. From within the app folder, what should my ack command look like?</p>