PHP マニュアル: Gets previously set hook on function or method

Closure uopz_get_hook(string $function)

Closure uopz_get_hook(string $class, string $function)

Gets the previously set hook on a function or method.

Returns the previously set hook on a function or method, or null if no hook has been set.

例1 Basic uopz_get_hook Usage

<?php
function foo() {
    echo 'foo';
}
uopz_set_hook('foo', function () {echo 'bar';});
var_dump(uopz_get_hook('foo'));
?>

上の例の出力は、たとえば以下のようになります。

object(Closure)#2 (0) {
}