1 function download($filename){ 
 2 
 3     if ((isset($filename))&&(file_exists($filename))){ 
 4 
 5        header("Content-length: ".filesize($filename)); 
 6 
 7        header('Content-Type: application/octet-stream'); 
 8 
 9        header('Content-Disposition: attachment; filename="' . $filename . '"'); 
10 
11        readfile("$filename"); 
12 
13     } else { 
14 
15        echo "Looks like file does not exist!"; 
16 
17     } 
18 
19 }
20 
21 //使用方法如下
22 
23 download('/down/test_45f73e852.zip');