title: printing process output in realtime
body: <p>I am using PHP 5.3.4 with Apache 2.2.17 on a Windows 7 x64 system.  I would like to have my PHP page output the result of a <code>system</code> call in real-time to the user's browser. To that end, I have configured <code>output_buffering=Off</code> in php.ini and created this code:</p>
  
  <pre><code>&lt;?php
  ob_implicit_flush(true);
  ob_end_flush();
  system('ping -n 10 www.google.com');
  ?&gt;
  </code></pre>
  
  <p>The result of the ping is printed in real-time, but I also get a PHP diagnostic error and callstack at the top of my page that says:</p>
  
  <pre><code>Notice: ob_end_flush() [ref.outcontrol]: failed to delete and flush buffer. No buffer to delete or flush in index.php on line 3
  </code></pre>
  
  <p>What do I need to do to either correct or suppress this error?</p>
  
  <p><strong>Update</strong>
  If I change <code>ob_end_flush()</code> to <code>$a = 1/0;</code> I get a similar error and the output is realtime in all browsers. Is it something about the way the exception is printed that causes this to work?</p>