title: Truncate string with Rails?
body: <p>I want to truncate a string as follows:</p>
  
  <p><strong>input:</strong></p>
  
  <pre><code>string = "abcd asfsa sadfsaf safsdaf aaaaaaaaaa aaaaaaaaaa dddddddddddddd"
  </code></pre>
  
  <p><strong>output:</strong></p>
  
  <pre><code>string = "abcd asfsa sadfsaf safsdaf aa...ddddd"
  </code></pre>