怎么样使用php自定义扩展名获取函数？

<?php
$url = "http://www.abc.com/abc/de/fg.php?id=1";
//这个是自己写的
function getUrl($url) {
 $date = explode('?', $url);
 $date = basename($date[0]);
 $date = explode('.', $date);
 return $date[1];
}
var_dump(getUrl($url));
//下面两个是网上弄的
function getExt($url){
 $arr = parse_url($url);
 $file = basename($arr['path']);
 $ext = explode(".",$file);
 return $ext[1];
}
var_dump(getExt($url));
function getName($url) {
 $w_param = pathinfo($url);
 $str = $w_param['extension'];
 list($type, $vars) = explode('?',$str);
 return $type;
}
echo 'start3'.date("Y-m-d H:i:s");