How to check if the Memcache extension is installed or enabled in your PHP setup?
List all loaded PHP modules and filter for memcache:
php -m | grep memcache
Query PHP for the memcache extension info:
php -i | grep memcache
Check if the Memcache class exists in PHP command line:
php -r "echo class_exists('Memcache') ? 'Memcache installed' : 'Memcache not installed';"
For web PHP, verify with a phpinfo() page or a similar script.
