Please run:
Should look:
Code
~# sudo -u www-data -H /opt/php-5.4/bin/php-cgi -v
PHP 5.4.42 (cgi-fcgi) (built: Jun 14 2015 10:46:39)
Copyright (c) 1997-2014 The PHP Group
Zend Engine v2.4.0, Copyright (c) 1998-2014 Zend Technologies
~#
Missing librarys will be shown - although the package does install those automatically.