Change Active Version of PHP

If you have several version of PHP installed, you can switch between them at anytime.

For this example, I have have installed PHP 7.4 and PHP 8.0

To change between them you use the update-alternatives command which will display available versions and let you choose which one you want active:

sudo update-alternatives --config php

To test the active version simply run:

php -v

You also need to tell Apache which module to enable. Below are the commands to disable PHP 7.4 and enable PHP 8.0:

sudo a2dismod php7.4
sudo a2enmod php8.0
sudo systemctl restart apache2