在运行时使用PHP删除函数(不带runkit扩展名) [英] Removing a function at runtime in PHP (without the runkit extension)

问题描述

我知道这个问题似乎很怪异，但是有什么方法可以在运行时用PHP删除函数吗?

I know this question seems hacky and weird, but is there a way to remove a function at runtime in PHP?

我有一个在"if"块中声明的递归函数，并且希望该函数仅在该"if"块中才是有效"的.我不希望在此块之外调用此函数.

I have a recursive function declared in a "if" block and want that function to be "valid" only in that "if" block. I don't want this function to be callled outside this block.

我发现了 runkit_function_remove ，但

I found out runkit_function_remove but runkit isn't enabled on my Web host. Is there another way to do that?

顺便说一句，我只支持PHP 5.1.0.

BTW I only support PHP 5.1.0.

我知道我的问题很棘手，但这正是我想做的事情:

I knew my question was hacky but here is the exact thing I want to do:

if (function_exists('get_magic_quotes_gpc') && @get_magic_quotes_gpc())
{
    function stripslashes_deep($value)
    {
        return is_array($value) ? array_map('stripslashes_deep', $value) : stripslashes($value);
    }

    $_POST = array_map('stripslashes_deep', $_POST);
    $_GET = array_map('stripslashes_deep', $_GET);
    $_COOKIE = array_map('stripslashes_deep', $_COOKIE);
    $_REQUEST = array_map('stripslashes_deep', $_REQUEST);

    //runkit_function_remove('stripslashes_deep');
}

由于"Stripslashes_deep"仅在魔术引号"处于启用状态时才有效，因此我想在使用完它后摆脱它.我不希望人们依赖并非总是有的功能.我希望现在更加清楚.也欢迎非hacky解决方案建议！

Since "stripslashes_deep" will only live when Magic Quotes are ON, I wanted to get rid of it when I'm done with it. I don't want people to rely on a function that isn't always there. I hope it's clearer now. Non-hacky solution suggestions are welcome too!

推荐答案

来自

PHP中的所有函数和类都具有全局作用域-即使在函数内部定义它们，也可以在函数外部调用它们，反之亦然. [...] PHP不支持函数重载，也无法取消定义或重新定义先前声明的函数.

All functions and classes in PHP have the global scope - they can be called outside a function even if they were defined inside and vice versa. [...] PHP does not support function overloading, nor is it possible to undefine or redefine previously-declared functions.

该异常是通过runkit进行的.但是，您可以将函数定义为匿名函数和 unset 运行后，例如

The exception is through runkit. However, you could define your function as an anonymous function and unset it after you ran it, e.g.

if (function_exists('get_magic_quotes_gpc') && @get_magic_quotes_gpc())
    $fn = create_function('&$v, $k', '$v = stripslashes($v);'); 
    array_walk_recursive(array(&$_GET, &$_POST, &$_COOKIE, &$_REQUEST), $fn);
    unset($fn);
}

一些评论者正确地指出了(但如今在PHP中已不再是问题)，您不能在其内部调用匿名函数.通过使用array_walk_recursive，您可以绕开此限制.就个人而言，我只会创建一个常规函数，而不必为删除它而烦恼.它不会伤害任何人.只需给它起一个适当的名称即可，例如stripslashes_gpc_callback.

Some commentors correctly pointed out (but not an issue any longer in PHP nowadays), you cannot call an anonymous function inside itself. By using array_walk_recursive you can get around this limitation. Personally, I would just create a regular function and not bother about deleting it. It won't hurt anyone. Just give it a proper name, like stripslashes_gpc_callback.

注意:评论后进行了编辑和压缩

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