Ubuntu 18.10 switch php7.1 and php7.2

README.txt

ATM php7.2 is current to Ubuntu.
Add php7.1 through:

sudo add-apt-repository ppa:ondrej/php
sudo apt-get update
sudo apt-get install php7.1
sudo apt-get install php7.1-cli php7.1-common php7.1-json php7.1-opcache php7.1-mysql php7.1-mbstring php7.1-mcrypt php7.1-zip php7.1-fpm php7.1-dev php7.1-curl php7.1-xml

Switch with script

phpswitch71.sh

#!/bin/bash
sudo a2dismod php7.2
sudo a2enmod php7.1
sudo service apache2 restart
# Avoid start-limit-hit
sleep 10s

sudo update-alternatives --set php /usr/bin/php7.1
sudo update-alternatives --set phar /usr/bin/phar7.1
sudo update-alternatives --set phar.phar /usr/bin/phar.phar7.1
sudo update-alternatives --set phpize /usr/bin/phpize7.1
sudo update-alternatives --set php-config /usr/bin/php-config7.1
sudo service apache2 restart