/**  * Enhanced force_download, can accept file in server  * @author Wilson Zeng  * @param $filename | The name that will use as the download file's name by default  * @param $data | Can be: [1]. a file real path; [2]. an string that contain the file's content  * @param $is_file | To specify the type of the $data  * @return Byte Stream */ function exforce_download($filename = '', $data = '', $is_file = FALSE) {
   if ($filename == '' OR $data == '')         {
   return FALSE;         } if($is_file && !is_file($data)){
   return FALSE;         } // Try to determine if the filename includes a file extension.         // We need it in order to set the MIME type         if (FALSE === strpos($filename, '.'))         {
   return FALSE;         } // Grab the file extension         $x = explode('.', $filename); $extension = end($x); // Load the mime types         /*zcs=Reduce Dependence         if (defined('ENVIRONMENT') AND is_file(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT))         {
                    include(APPPATH.'config/'.ENVIRONMENT.'/mimes'.EXT);         }         elseif (is_file(APPPATH.'config/mimes'.EXT))         {
                    include(APPPATH.'config/mimes'.EXT);         } */ $mimes = array(); //zcs=[NOTE] Here we just assign an empty array to reduce the dependence of the CI framework         // Set a default mime if we can't find it         if ( ! isset($mimes[$extension]))         {
   $mime = 'application/octet-stream';         } else         {
   $mime = (is_array($mimes[$extension])) ? $mimes[$extension][0] : $mimes[$extension];         } $size = 0; if($is_file){
   $size = filesize($data);         }else{
   $size = strlen($data);         } // Generate the server headers         if (strpos($_SERVER['HTTP_USER_AGENT'], "MSIE") !== FALSE)         {
   header('Content-Type: "'.$mime.'"'); header('Content-Disposition: attachment; filename="'.$filename.'"'); header('Expires: 0'); header('Cache-Control: must-revalidate, post-check=0, pre-check=0'); header("Content-Transfer-Encoding: binary"); header('Pragma: public'); header("Content-Length: ".$size);         } else         {
   header('Content-Type: "'.$mime.'"'); header('Content-Disposition: attachment; filename="'.$filename.'"'); header("Content-Transfer-Encoding: binary"); header('Expires: 0'); header('Pragma: no-cache'); header("Content-Length: ".$size);         } if($is_file){
   $h_file = fopen($data, 'r'); while(!feof($h_file)){
   echo fread($h_file, 1048576);//1M                 } fclose($h_file);         }else{
   exit($data);         } }