You can create an INI configuration file for your project and the parse it using php parse_ini_file function.
http://php.net/manual/en/function.parse-ini-file.php
Sample INI file
; This is a sample configuration file
; Comments start with ';', as in php.ini
[first_section]
one = 1
five = 5
animal = BIRD
[second_section]
path = "/usr/local/bin"
URL = "http://www.example.com/~username"
[third_section]
phpversion[] = "5.0"
phpversion[] = "5.1"
phpversion[] = "5.2"
phpversion[] = "5.3"
Here is another example for PHP configuration patterns
h++p://www.ibm.com/developerworks/library/os-php-config/index.html