title: PHP: imagemagick creates empty image with convert
body: <p>I have a script that is supposed to take an image and convert it to a .jpg. This is the code that makes it happen:</p>
  
  <pre><code>$uploadDir = $_SERVER['DOCUMENT_ROOT'] . "/blogimages/";
  $tempFile = ereg_replace("'", "_", basename($_FILES['newsImg']['name']));
  $uploadFile = $uploadDir . $tempFile;
  move_uploaded_file($_FILES['newsImg']['tmp_name'], $uploadFile);
  $newPic = $uploadDir . $blogID . ".jpg";
  if(file_exists($newPic)){
  unlink($newPic);
  }
  $convertString = "$IM -strip $uploadFile $newPic";
  echo "&lt;!-- $convertString --&gt;";
  exec($convertString);
  </code></pre>
  
  <p>as can be seen I put the final string in an HTML comment so I can see what is being executed. What happens is that the converted image is created, but it is a 0 byte image. So no data is actually written to the file. Just to make sure convert is actually working like it normally should I copy and pasted the convert string from the html comment to a command line and it works just fine. It only seems to be having problems within the PHP exec. Any thoughts on why this might be?</p>