/**
* 得到文件目录的大小/此数据只是大小数据,而不是所占用的空间
*/
function dirsize($dirname)
{
if(stripos(PHP_OS, "win")!==false){//For Windows
   $obj = new COM ( 'scripting.filesystemobject' );
   if ( is_object ( $obj ))
   {
    $ref = $obj->getfolder ( $dirname );
    $size = $ref->size;
    $obj = null;
    return $size;
   }
   else{
    return false;
   }
}else{// For Linux-like
   $io = popen ( '/usr/bin/du -sk ' . $dirname, 'r' );
   $size = fgets ( $io, 4096);
   $size = substr ( $size, 0, strpos ( $size, ' ' ) );
   pclose ( $io );
   return $size;
}
}


echo dirsize("E:")/(1024*1024);