title: How many open files in PHP?
body: <p>Is there a function in PHP to query the number of open files?  </p>
  
  <p>Sort of like <code>memory_get_usage()</code> but for open files.</p>
  
  <p>I'm running the unit test suites for Zend Framework.  The problem is that after it gets through the tests for Zend_Search_Lucene, subsequent tests start failing.  But if I skip the Zend_Search_Lucene tests, all the test suites succeed.</p>
  
  <p>I'd like to prove that Zend_Search_Lucene (or any other test suite) is opening too many files and not cleaning up after itself.  I thought PHP might have a function to simply report how many files are open.  But after 20 minutes of searching the PHP manual and Google, I can't find any such function. </p>