Is it required to run install script after adding new server or PHP modules?

No, once WordPress is installed, you don’t need to run WordPress’s install script again.

Hello James,
Thank you for your replay!

Is there a way to see features currently supported and how wordpress knows that I have installed new modules in oreder to start using them?

The only thing that I know is built into WordPress is Site Health screen. That will tell you if there’s anything missing, but doesn’t list what’s installed.

The easy way to find out what’s available to be used is to add in a phpinfo file somewhere on your site and see what that outputs. That’s as easy as this:

<?php phpinfo ();

Thank you for your replay catacaustic!

I am mainly interested whether memcached, opcache, redis and filter modules are working and how

phpinfo is not suitable because it shows modules installed and their status but that doesn;t mean they are used by wordpress, so health page looks more helpful because I checked that it verifies if modules are active or not

By the way your php tag is not closed and phpinfo will not work ??

By the way your php tag is not closed and phpinfo will not work

Nope, what I have is right. ??

You don’t need a closing ?> tag in a PHP file. It’s only needed if you’re breaking out of PHP into straight HTML. If your file ends with PHP code then you shouldn’t include the ending tag.

https://www.php.net/manual/en/language.basic-syntax.instruction-separation.php

The first line in the notes there…

The closing tag of a PHP block at the end of a file is optional

If a PHP extension is installed and shows up on the phpinfo() page, then WordPress will know it is available. That’s how PHP scripts work. Site Health will ALWAYS show the same information as running phpinfo() from a web-facing script. Note that running php -r "phpinfo();" or php -i from the command line can display different results than running phpinfo() from a web-facing script.

I’m sure you already know, but for others reading this: if PHP extensions are added/removed, one must restart PHP in order for the new configuration to take effect.

Hello guys,
Thank you for your replays

@catacaustic
I will try it to see what happens id closing tag is missing, but I think it is not good idea, because I used this code <=? phpinfo(); ?> that with php8.1 is not working anymore and phpinfo function doesn;t run

@diondesigns
I restart/reload webserver and not php, because there is no php instance running

I used this code <=? phpinfo(); ?> that with php8.1 is not working anymore and phpinfo function doesn;t run

Then perhaps you have not compiled PHP correctly?

That is a valid function even in PHP 8: https://www.php.net/manual/en/function.phpinfo.php

there is no php instance running

Ah, well that explains it.

If PHP isn’t running, then nothing that uses PHP will run.

PHP is not like an app that only runs when you need it, it’s part of the core server architecture.

It sounds like you’ll need to recompile your server again and ensure that PHP is properly compiled with it.