title: php - move_uploaded_file - why is it important?
body: <p>I cannot imagine why should I use this function instead of a simple rename.</p>
  <p>The manual writes:</p>
  <blockquote>
  <p>move_uploaded_file</p>
  <p>This function checks to ensure that the file designated by filename
  is a valid upload file (meaning that it was uploaded via PHP's HTTP
  POST upload mechanism). If the file is valid, it will be moved to the
  filename given by destination.</p>
  <p>This sort of check is especially important if there is any chance that
  anything done with uploaded files could reveal their contents to the
  user, or even to other users on the same system.</p>
  </blockquote>
  <p>Can you please write an example why is this so important?</p>