Is it possible to define a PHP class server wide?

Question

What I am asking is something like declaring environment variable in Apache for PHP like

SetEnv SITE_MAIN_DIR "/var/www/www.mydomain.com/"

That I can access anywhere in the site and it works great.

echo $_SERVER['SITE_MAIN_DIR']

Does PHP have similar to this for global classes so that I do not have to use include /dir/class.php ;

class::function($string); without using include?

Answer 1

You can use getenv()

echo getenv(SITE_MAIN_DIR);   

https://www.php.net/manual/en/function.getenv.php

But I would consider using an autoloader.

Answer 2

PHP 7.4 有一个名为opcache preloading的新功能，也许这就是您正在寻找的。