织梦dedecms图片按月存放怎么实现？代码分享

//获得下载媒体的随机名称
function GetRndName($url,$v)
{
global $cfg_image_dir,$cfg_dir_purview;
$this->mediaCount++;
$mnum = $this->mediaCount;
$timedir = "c".MyDate("ym（修改些处，去掉原有的d即可按月存放，同理以你自己喜欢的来设定吧）",time());
//存放路径
$fullurl = preg_replace("//{1,}/","/",$cfg_image_dir."/");
if(!is_dir($GLOBALS['cfg_basedir']."/$fullurl"))
{
MkdirAll($GLOBALS['cfg_basedir']."/$fullurl",$cfg_dir_purview);
}
$fullurl = $fullurl.$timedir."/";
if(!is_dir($GLOBALS['cfg_basedir']."/$fullurl"))
{
MkdirAll($GLOBALS['cfg_basedir']."/$fullurl",$cfg_dir_purview);
}