title: Automatically downloading images from any URL location
body: <p>I have a serious problem in the late stage of a project I'm working on:</p>
  
  <p>I wrote a PHP function that makes it possible for a user to download an image automatically on a hard drive by clicking on its link.
  But that was easy because the image was uploaded to the website server and I knew it's full server address.
  For Example: <code>"home/clients/websites/w_apo/public_html/wp-content/uploads/image.jpg"</code></p>
  
  <p>But now the client wants the ability to paste the image URL from his own address <code>http://www.something.com/image.jpg</code> and still be able to automatically download that image by clicking on the link on the frontend.</p>
  
  <p>I'm kind of new in this area of programming so I really need your help. Any links, advice, resources are most welcome.</p>
  
  <p>Thanks!</p>
  
  <p>This is my current function for downloading:</p>
  
  <pre><code>download_file($_GET['file']);
  
  /******************************************************************/
  
  function download_file( $fullPath ){
  
    // Must be fresh start
    if( headers_sent() )
      die('Headers Sent');
  
    // Required for some browsers
    if(ini_get('zlib.output_compression'))
      ini_set('zlib.output_compression', 'Off');
  
    // File Exists?
    if( file_exists($fullPath) ){
  
      // Parse Info / Get Extension
      $fsize = filesize($fullPath);
      $path_parts = pathinfo($fullPath);
      $ext = strtolower($path_parts["extension"]);
  
      // Determine Content Type
      switch ($ext) {
        case "pdf": $ctype="application/pdf"; break;
        case "exe": $ctype="application/octet-stream"; break;
        case "zip": $ctype="application/zip"; break;
        case "doc": $ctype="application/msword"; break;
        case "xls": $ctype="application/vnd.ms-excel"; break;
        case "ppt": $ctype="application/vnd.ms-powerpoint"; break;
        case "gif": $ctype="image/gif"; break;
        case "png": $ctype="image/png"; break;
        case "jpeg":
        case "jpg": $ctype="image/jpg"; break;
        default: $ctype="application/force-download";
      }
  
      header("Pragma: public"); // required
      header("Expires: 0");
      header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
      header("Cache-Control: private",false); // required for certain browsers
      header("Content-Type: $ctype");
      header("Content-Disposition: attachment; filename=\"".basename($fullPath)."\";" );
      header("Content-Transfer-Encoding: binary");
      header("Content-Length: ".$fsize);
      ob_clean();
      flush();
      readfile( $fullPath );
  
    } else
      die('File Not Found');
  
  }
  </code></pre>