エラー処理関数
PHP マニュアル

get_error_handler

Gets the user-defined error handler function

説明

callablenull get_error_handler()

Returns the current error handler function, if any.

パラメータ

この関数にはパラメータはありません。

戻り値

Returns the currently defined error handler (if any). If the built-in error handler is used null is returned.

The returned handler is the exact callable value that was passed to set_error_handler to define it.

例

例1 get_error_handler example

<?php

$handler = function (int $errno, string $errstr, ?string $errfile, ?int $errline) {
     echo "Error: " . $errstr . "\n";
};

var_dump(get_error_handler()); // NULL

set_error_handler($handler);

var_dump(get_error_handler() === $handler); // bool(true)

?>

注意

ヒント

Prior to PHP 8.5.0, this functionality can be provided by the following polyfill: 

<?php
if (!function_exists('get_error_handler')) {
    function noop_error_handler() {
    }
    function get_error_handler(): ?callable {
        $handler = set_error_handler('noop_error_handler');
        restore_error_handler();
        return $handler;
    }
}
?>

参考