Magento 2.2 with PHP 7.1.9 Issue
Soluzione
As you can see, still your PHP server is using 5.6.31 version. So you need to upgrade your PHP in order to use Magento 2.2
EDIT
Your console is still relying on PHP version 5.6.x. It is true that using your MultiPHP manager you are running your site on version 7.x. But it means your apache PHP version is only changed. However, CLI is not relying on Apache configuration, which still relies on your default PHP setup. So you need to upgrade that too.
You can fix this in many ways. A good start is here. Then look for the best way that will work for you.
Altri suggerimenti
If the above approaches do not work (they did not work for me), explicitly recite the php version on the command line:
/usr/local/php71/bin/php /home/your-magento-directory/bin/magento cache:clear
or
/usr/local/php71/bin/php /home/your-magento-directory/bin/magento other-magento-command
Before running any php command on my vps with plesk panel I run:
export PATH=/opt/plesk/php/7.0/bin:$PATH
or
export PATH=/opt/plesk/php/7.1/bin:$PATH
After that
php bin/magento indexer:reindex
or any php magento command
When you have multiple PHP version on your server then you need to specify the php version in command line because from multiple PHP version, one PHP version is set as Default so please run below command for PHP7.1:
/opt/plesk/php/7.1/bin/php bin/magento cache:flush; /opt/plesk/php/7.1/bin/php bin/magento indxer:reindex;
Try it.
use this command for executing this specific command in PHP 7.2
/etc/php/7.2 php /home/tm/dockercontainer/magento2folder/bin/magento sampledata:deploy