ubuntu 18.04 change from php7 to php5 code example
Example: change php version ubuntu
//In ubunutu
Default PHP 7.1 is set on your system and you need to switch to PHP 5.6
$ sudo a2dismod php7.1
$ sudo a2enmod php5.6
$ sudo service apache2 restart
sudo update-alternatives --set php /usr/bin/php5.6