Here is the list of Database connection file locations of various CMS in cPanel. If you are installing it on Plesk the public_html will become httpdocs.
(1) Wordpress : public_html/wp-config.php
(2) OSCommerce : public_html/catalog/includes/configure.php
OS Commerce Admin : admin/includes/configure.php
(3) Joomla : public_html/configuration.php
(4) Drupal : public_html/settings.php
Public_html is the default root location for the cPanel and httpdocs is the default root location for Plesk. Suppose, your application is hosted on the blog directory inside public_html, the path will become as below.
(1) Wordpress : public_html/blog/wp-config.php
(2) OSCommerce : public_html/blog/catalog/includes/configure.php
OS Commerce Admin : admin/includes/configure.php
(3) Joomla : public_html/blog/configuration.php
(4) Drupal : public_html/blog/settings.php
