# Mysqli is installed on my system and the extension is enabled in php.ini but I can't find the actual extension

Centos 6.4 X86_64 with Apache 2.2.4 and PHP 5.4.17. I've rebuilt PHP to include mysqli. Phpinfo shows mysqli installed. Php.ini has the extension un-commented. How do I get the mysqli.so into the lib/php/extensions/no-debug-non.../ directory? I apologize if I left something out - I'm a Linux noob. I've searched all over for similar issues but none of the fixes seem to work to actually get mysqli.so into the extension directory. Thanks.

extension_dir = "C:\PHP7\ext"