string get_cfg_var (string varname)
Returns the current value of the PHP configuration variable specified by varname, or false if an error occurs.
It will not return configuration information set when the PHP was compiled, or read from an Apache configuration file (using the php3_configuration_option directives).
To check whether the system is using a configuration file, try retrieving the value of the cfg_file_path configuration setting. If this is available, a configuration file is being used.