If you have zend installed you should be able to find the php.ini, at /usr/local/Zend/etc/php.ini

but you can find out the location of php.ini from the shell type
Code:
php -i | grep php.ini
that will give you location of the php.ini file

or you can just make phpinfo.php file with content
CODE
<?php
phpinfo();
?>

which will also give the location of the php.ini file