title: Download any file using PHP
body: <p>How can I download files(text/pdf/etc) using php with a header that pops-up in order for the user to choose Save or Open? The file is stored in (admin/)</p>
  
  <p>I'm using this but it won't work. The downloaded file is empty!
  Here's my code:    </p>
  
  <pre><code> //get the filename
  $filename = $_GET['filename'];
  
  //open the file based in filename and path
  $fp = fopen('admin/'.$filename, 'w') or die("can't open file");
  
  
  header("Content-type:  text/pdf");
  header("Content-Disposition: attachment; filename=file.txt");
  header("Cache-Control: must-revalidate, post-check=0, pre-check=0");        
  
  //echo file_get_contents($filename);
  exit;   
  </code></pre>