title: Display only matched string with grep
body: <p>I have a file that I want to match that looks like the following:</p>
  
  <pre><code>...
  new VideoInfo(6, VideoType.Flash, 270, false, AudioType.Mp3, 64, AdaptiveType.None),
  new VideoInfo(13, VideoType.Mobile, 0, false, AudioType.Aac, 0, AdaptiveType.None),
  new VideoInfo(17, VideoType.Mobile, 144, false, AudioType.Aac, 24, AdaptiveType.None),
  ... [a few hundred more entries like these]
  </code></pre>
  
  <p>And I have the following regex pattern to match the first number:</p>
  
  <pre><code>grep "new VideoInfo(.*," VideoInfo.cs
  </code></pre>
  
  <p>The trouble is, grep emits the entire line that was matched instead of just <code>6 13 17 ...</code>.</p>
  
  <p>How can I get it to echo only the matched results?</p>
  
  <hr>
  
  <p><strong>EDIT:</strong> I have trailing whitespace in front of each <code>new VideoInfo ...</code> line.</p>