yii\web\Request::getScriptFile PHP Method

    public function getScriptFile()
    {
        if (isset($this->_scriptFile)) {
            return $this->_scriptFile;
        } elseif (isset($_SERVER['SCRIPT_FILENAME'])) {
            return $_SERVER['SCRIPT_FILENAME'];
        } else {
            throw new InvalidConfigException('Unable to determine the entry script file path.');
        }
    }