1. 写一个函数，尽可能高效的，从一个标准 url 里取出文件的扩展名
例如: http://www.sina.com.cn/abc/de/fg.php?id=1 需要取出 php 或 .php
<?php $url = "http://www.sina.com.cn/abc/de/fg.php?id=1 ";
//这个是自己写的function getUrl($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");?>