脚本崩溃中的自定义错误消息？ PHP

I've never worked with advanced error handling, and I can't find an obvious answer searching.

In the scope a script (require_once) how do you set up a custom "die" message?

Generally my users see the page-load die with no response. I'd like to direct them to a help file regarding memory so they absolutely cannot miss the solution.

You can kill a script and output a message using the die() command

die("Your message here");

You can also throw custom exceptions in PHP 5+, and catch them and at that point output a message to the users.

http://php.net/manual/en/language.exceptions.php

require_once automatically stops execution if it fails.

Try e.g. (include_once file.php) or header('Location: http://.../path/to/help');, or

if(!(include_once file.php)) {
    // redirect?
}