Php require_once __dir__
- Php require_once directory
- Php require_once dirname (__ file __)
- Php require_once root directory
- Php require_once up one directory
- Php require_once parent directory
- Php require_once current directory
- Php require_once same directory
- Php require_once from different directory
- Php require_once back one directory
- Php require_once all files in directory