title: Perl ack tool with output parameter and new lines
body: <p>I use <code>ack</code> very often, but something I have not been able to discover is how to make it add new lines when using the output parameter.</p>
  
  <p>Example</p>
  
  <pre><code>echo 'name=Joe,id=123' | ack '^name=(\w+),id=(\d+)' --output="User name: $1\nUser ID: $2"
  </code></pre>
  
  <p>I expect</p>
  
  <pre><code>User name: Joe
  User ID: 123
  </code></pre>
  
  <p>but I get</p>
  
  <pre><code>User name: Joe\nUser ID: 123
  </code></pre>
  
  <p>Anyway to make <code>ack</code> respect the new lines characters in the output?</p>
  
  <p>Thanks</p>