You can get location path of php.ini file using php_ini_loaded_file() of PHP. Sometimes we require to get php.ini file path. So, if you need to get path of php confogration file then you can get following way:
Example:
print_r(php_ini_loaded_file());
You can find output something like bellow if you are use ubuntu system:
/etc/php5/apache2/php.ini