public function getWebSrvUserGroup($username = null) {
		$result = '';
		if ($this->isOsWindows() || empty($username)) {
			return $result;
		}

		$cmd = 'groups ' . $username . ' | head -1 | cut -d\  -f1 2>/dev/null';
		$output = [];
		$exitCode = -1;
		exec($cmd, $output, $exitCode);
		if (($exitCode !== 0) || (count($output) < 1)) {
			return $result;
		}

		$result = array_shift($output);

		return $result;
	}