PHP下载页面的处理代码

function get_extension($file){     
 　　return substr(strrchr($file, '.'), 1); 
} 
function get_name($path){     
   return substr(strrchr($path, '/'), 1); 
} 
function getImage($url,$fileName="") {
   $fbufsize = 8096;
   $ext = get_extension($url);      
   $fileName = get_name($url);  
   $type = array(
   'gif' => 'image/gif',
   'jpeg' => 'image/jpeg',
   'jpg' => 'image/jpeg',
   'jpe' => 'image/jpeg',
   'png' => 'image/png',
   );
                                                                                
$imgType = isset($type[$ext])?$type[$ext]:die("类型不符");
header('Content-Description: File Transfer');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Pragma: public');
header("Content-type: ".$imgType);
header("Content-Transfer-Encoding: binary");
header('Content-Disposition: attachment; filename="'.$fileName.'"');      
header("Content-Length:" . getimagesize($url)."\n\n" ); 
$fp = fopen($url,"r");
while(!feof($fp)) {
   print(fread($fp,$fbufsize));
   flush();
   ob_flush();
}
   fclose($fp);
   exit;
}  
getImage("http://snowcoal.com/IMAGES_6930/201407/1405910422162.jpg");