The following command will list all of the PHP *.ini configuration files it is using. This is for php-cli.
me@box:~$ php --ini Configuration File (php.ini) Path: /etc/php5/cli Loaded Configuration File: /etc/php5/cli/php.ini Scan for additional .ini files in: /etc/php5/cli/conf.d Additional .ini files parsed: /etc/php5/cli/conf.d/curl.ini, /etc/php5/cli/conf.d/ffmpeg.ini, /etc/php5/cli/conf.d/gd.ini, /etc/php5/cli/conf.d/ldap.ini, /etc/php5/cli/conf.d/memcache.ini, /etc/php5/cli/conf.d/mysql.ini, /etc/php5/cli/conf.d/mysqli.ini, /etc/php5/cli/conf.d/oci8.ini, /etc/php5/cli/conf.d/override_defaults.ini, /etc/php5/cli/conf.d/pdo.ini, /etc/php5/cli/conf.d/pdo_mysql.ini |
Do this with Apache: