title: PHP Bad File Descriptor Error
body: <p>We've recently upgraded our servers from PHP 5.4.15 to 5.5.1 and have started getting this error in the logs </p>
  
  <blockquote>
    <p>Fatal Error Unable to create lock file: Bad file descriptor</p>
  </blockquote>
  
  <p>I've tracked it down to this bit a code that opens another small PHP script which uploads a file to S3 in the background.</p>
  
  <pre><code>// Grab uploaded file and assign a working name
  $fileTemp = $_FILES['file']['tmp_name'];
  $pathToWorkingFile = tempnam($g_TmpDirectory, "TR-");
  
  // Move the file to our working area        
  if (move_uploaded_file($fileTemp, $pathToWorkingFile) === false)
      throw new Exception("Cannot move file to staging area.", 1011);
  
  // Where the file will end up on S3
  $s3Bucket = "test.bucket.com";
  $uploadDest = "/uploads/image123.jpg";
  
  // Create process to upload file in background
  popen("/usr/local/bin/php /path/to/uploadScript.php $pathToWorkingFile $s3Bucket $uploadDest &amp;", 'r');
  </code></pre>