**一.Get_defined_functions改进禁用函数** #php.ini:disable_functions=substr 1.代码实例 ``` function Foo(string $name,int $age){ return "$name,$age"; } function substr(){ echo 23; } $ref=get_defined_functions(); echo "<pre>"; print_r($ref); echo "</pre>"; ``` 2.低版本 ``` Fatal error: Cannot redeclare substr() ``` 3.新版本 ``` [user] => Array ( [0] => foo [1] => substr ) ```