請問如何透過PHP新增filezilla server的FTP使用者，並設定Home dir
目前試過透過編輯xml的方式

	public function create_user($user_name, $password, $ftpUserFolder, $createBackup = true, $reloadFTP = true)
	{
		$xmlfile = FTP_CONF_FILE;
		$xmlfolder = dirname(FTP_CONF_FILE);

		$xmlbackupfile = @date("Y-m-d-H-i-s") . '_FileZilla_Server.xml';

		$xml = simplexml_load_file($xmlfile);
		// Copy Config for backup before each change, too.

		$isvalid = $this->filezilla_ftp->isUserID($user_name);
		if (!$isvalid) {
			echo "Username $user_name is invalid\n";
			return false;
		}
		if ($this->filezilla_ftp->check_user_exists($xml, $user_name)) {
			echo "Username $user_name already exists...\n";
			return false;
		}
		if ($createBackup) {
			if (!copy($xmlfile, $xmlbackupfile)) {
				echo "Problem creating xml backup file";
				return false;
			}
		}


		$salt = "";
		while (strlen($salt) !== 64) {
			$byte = ord(openssl_random_pseudo_bytes(1));
			if ($byte > 31 && $byte < 127) {
				$salt .= chr($byte);
			}
		}

		$hashed_password = strtoupper(hash('SHA512', $password . $salt));

		$xml = simplexml_load_file($xmlfile);
		$Pass = $xml->xpath("//User[@Name='TheUserName']//Option[@Name='Pass']");
		$Salt = $xml->xpath("//User[@Name='TheUserName']//Option[@Name='Salt']");

		$Pass[0][0] = $hashed_password;
		$Salt[0][0] = $salt;

		$user = $xml->Users->addChild('User');
		$user->addAttribute('Name', $user_name);

		$this->filezilla_ftp->add_option($user, 'Pass', $hashed_password);
		$this->filezilla_ftp->add_option($user, 'Group', null);
		$this->filezilla_ftp->add_option($user, 'Bypass server userlimit', '0');
		$this->filezilla_ftp->add_option($user, 'User Limit', '0');
		$this->filezilla_ftp->add_option($user, 'IP Limit', '0');
		$this->filezilla_ftp->add_option($user, 'Enabled', '1');
		$this->filezilla_ftp->add_option($user, 'Comments', 'none');
		$this->filezilla_ftp->add_option($user, 'ForceSsl', '0');

		$filter = $user->addChild('IpFilter');
		$filter->addChild('Disallowed');
		$filter->addChild('Allowed');

		$permissions = $user->addChild('Permissions');
		$permission = $permissions->addChild('Permission');

		$permission->addAttribute('Dir', str_replace("/", "\\", $ftpUserFolder));

		$this->filezilla_ftp->add_option($permission, 'FileRead', '1');
		$this->filezilla_ftp->add_option($permission, 'FileWrite', '1');
		$this->filezilla_ftp->add_option($permission, 'FileDelete', '1');
		$this->filezilla_ftp->add_option($permission, 'FileAppend', '1');
		$this->filezilla_ftp->add_option($permission, 'DirCreate', '1');
		$this->filezilla_ftp->add_option($permission, 'DirDelete', '1');
		$this->filezilla_ftp->add_option($permission, 'DirList', '1');
		$this->filezilla_ftp->add_option($permission, 'DirSubdirs', '1');
		$this->filezilla_ftp->add_option($permission, 'IsHome', '1');
		$this->filezilla_ftp->add_option($permission, 'AutoCreate', '1');

		$speed = $user->addChild('SpeedLimits');
		$speed->addAttribute('DlType', '1');
		$speed->addAttribute('DlLimit', '10');
		$speed->addAttribute('ServerDlLimitBypass', '0');
		$speed->addAttribute('UlType', '1');
		$speed->addAttribute('UlLimit', '10');
		$speed->addAttribute('ServerUlLimitBypass', '0');
		$speed->addChild('Download');
		$speed->addChild('Upload');

		if (!$rv = $xml->asXML($xmlfile)) {
			echo('SimpleXML could not write file');
			return false;
		}
		//Change file encoding from UTF8 to ISO-8859-1
		$dom = new DOMDocument("1.0", "ISO-8859-1");
		$dom->preserveWhiteSpace = false;
		$dom->formatOutput = true;
		if (!$dom->load($xmlfile) || !$dom->save($xmlfile)) {
			echo('DOMDocument could not change file enconding from UTF8 to ISO-8859-1');
			return false;
		}
		if ($reloadFTP) {
			$ftpExecutable = '"' . FTP_EXE_FILE . '" /reload-config';
			$command = $ftpExecutable;
			system($command, $retval);
		}
		return true;
	}
	public function isUserID($username) {
		return preg_match('/^[A-Za-z0-9][A-Za-z0-9]*(?:_[A-Za-z0-9]+)*$/', $username);
	}
	public function isValid($str) {
		return !preg_match('/[^A-Za-z0-9\_\-]/', $str);
	}
	public function add_option($xmlobj, $name, $value) {
		$option = $xmlobj->addChild('Option', $value);
		$option->addAttribute('Name', $name);
	}
	public function check_user_exists($xml, $username) {
		$children = $xml->Users->children();
		foreach ($children as $child) {
			if ($child->getName() == 'User') {
				foreach ($child->attributes() as $attributes) {
					if (trim($attributes) == trim($username)) {
						echo "Username $username already exits... \n";
						return true;
					}
				}
			}
		}
		return false;
	}

(以上PHP使用codeigniter框架，放在model filezilla_ftp.php中)
但是卡在Pass 和 salt這兩個欄位