title: screen recorder with kitkat
body: <p>I'm developing a simple utility to record the screen of device using the new function of kitkat 4.4. So, I've create a button with various edit text for the parameters such as bit rate, seconds and file name. I've this code.</p>
  
  <pre><code>StringBuilder builder;
  builder = new StringBuilder("system/bin/screenrecorder");
  </code></pre>
  
  <p>When i retrieve the parameters do something like</p>
  
  <pre><code>builder.append(" --bit-rate ").append(editText.getText());
  </code></pre>
  
  <p>Finally I've the complete command to record, like</p>
  
  <p><strong>"system/bin/screenrecorder --size 720x1184 --bit-rate 5 --time-limit 5 /storage/emulated/0/MyVideos/example.mp4</strong>"</p>
  
  <p>My question now is this: </p>
  
  <p>How can i execute this command? In other words, what should I do now to start recording using the variable builder?</p>