title: How to return a character set after matching a specific string in a regular expression
body: <p>I'm actually using using a command line tool called <code>sox</code> to retrieve information about an audio file. This returns the following output:</p>
  
  <pre><code>Samples read:            449718
  Length (seconds):     28.107375
  Scaled by:         2147483647.0
  Maximum amplitude:     0.999969
  Minimum amplitude:    -0.999969
  Midline amplitude:     0.000000
  Mean    norm:          0.145530
  Mean    amplitude:     0.000291
  RMS     amplitude:     0.249847
  Maximum delta:         1.316925
  Minimum delta:         0.000000
  Mean    delta:         0.033336
  RMS     delta:         0.064767
  Rough   frequency:          660
  Volume adjustment:        1.000
  </code></pre>
  
  <p>I'd like to extract the values out of this using a regular expression. So far I have <code>/^Length \(seconds\):\s*[0-9.]*/m</code> which matches <code>Length (seconds):     28.107375</code> but I just want the value.</p>
  
  <p>What do I need to do?</p>