How to Switch between Multiple PHP Version on Debian 9

On your system, if you have installed multiple versions of PHP (eg PHP 7.2, 7.1 and 5.6). PHP 7.2 is running as default PHP for Apache and CLI. For any requirement, you need to use PHP 5.6. Then you don’t need to remove PHP 7.2. You can simply switch your PHP version to default used for Apache and command line.

We assume you have installed multiple PHP version on your Debian system. Now you need to switch the active PHP version for CLI and Apache2. This tutorial will help you to switch between multiple PHP versions for Apache server and CLI on Debian.

• Read => How to Install PHP on Debian 9 via PPA

Here are two examples for PHP 7.2 and PHP 5.6. You can use the same for other PHP versions by changes commands accordingly.

Enable PHP 7.2 as Default

You need to set PHP 7.2 as your active PHP version for CLI and Apache2 both. You can do this by disabling Apache2 modules for all other installed PHP versions and configure CLI using the update-alternatives command. Run the following commands to make changes.

Apache:-

sudo a2dismod php5.6 php7.1 php7.0   ## Shows error for modules not installed 
sudo a2enmod php7.2
sudo service apache2 restart

Command Line:-

sudo update-alternatives --set php /usr/bin/php7.2
sudo update-alternatives --set phar /usr/bin/phar7.2
sudo update-alternatives --set phar.phar /usr/bin/phar.phar7.2
sudo update-alternatives --set phpize /usr/bin/phpize7.2
sudo update-alternatives --set php-config /usr/bin/php-config7.2

Note – The phpize7.2 and php-config7.2 command is available in php7.2-dev package. This is more useful for compiling PHP modules using pecl.

Enable PHP 5.6 as Default

You need to set PHP 5.6 as your default version for CLI and Apache2 both. Run the following commands to disable other PHP versions like (php7.2, php7.1, or php7.0 etc) for Apache and command line.

Apache:-

sudo a2dismod php7.2 php7.1 php7.0    ## Shows error for modules not installed 
sudo a2enmod php5.6
sudo service apache2 restart

Command Line:-

sudo update-alternatives --set php /usr/bin/php5.6
sudo update-alternatives --set phar /usr/bin/phar5.6
sudo update-alternatives --set phar.phar /usr/bin/phar.phar5.6 
sudo update-alternatives --set phpize /usr/bin/phpize5.6
sudo update-alternatives --set php-config /usr/bin/php-config5.6

Note – The phpize5.6 and php-config5.6 command is available in php5.6-dev package. This is more useful for compiling PHP modules using pecl.