Running different version of Php on linux (Ubuntu)

You should have noticed some of your PHP webapps are not working after upgrading php to version 7. This is due to the fact that php 7 has removed a lot of previous deprecated php libraries. In order to install and use PHP 5 you this tutorial.

1. Re-Install PHP 5.6

Actually is not required to remove php7.0, you can install php5.6 together ( also because you will have dependency problem with phpmyadmin package that required php7.0)

Assuming libapache2-mod-php is a suitable way to enable PHP in Apache for you, you can proceed in this way:

sudo add-apt-repository ppa:ondrej/php

sudo apt-get update

sudo apt-get install php7.0 php5.6 php5.6-mysql php-gettext php5.6-mbstring php-xdebug libapache2-mod-php5.6 libapache2-mod-php7.0

2. Switch PHP version:

• From php5.6 to php7.0 :
  • Apache:
    sudo a2dismod php5.6 ; sudo a2enmod php7.0 ; sudo service apache2 restart
  • CLI:
    sudo ln -sfn /usr/bin/php7.0 /etc/alternatives/php
• from php7.0 to php5.6:
• Apache:
  sudo a2dismod php7.0 ; sudo a2enmod php5.6 ; sudo service apache2 restart
• CLI:
  sudo ln -sfn /usr/bin/php5.6 /etc/alternatives/php

Now you can switch in between php versions as you like.