<?php      /* set here a limit of downloading rate (e.g. 10.20 Kb/s) */      $download_rate = 10.20;              $download_file = 'download-file.zip';       $target_file = 'target-file.zip';              if(file_exists($download_file)){          /* headers */          header('Last-Modified: '.gmdate('D, d M Y H:i:s').' GMT');          header('Cache-control: private');          header('Content-Type: application/octet-stream');          header('Content-Length: '.filesize($download_file));          header('Content-Disposition: filename='.$target_file);                  /* flush content */          flush();                  /* open file */          $fh = @fopen($download_file, 'r');          while(!feof($fh)){              /* send only current part of the file to browser */              print fread($fh, round($download_rate * 1024));              /* flush the content to the browser */              flush();              /* sleep for 1 sec */              sleep(1);          }          /* close file */          @fclose($fh);      }else{          die('Fatal error: the '.$download_file.' file does not exist!');      }      ?>