/// <summary>

        /// 验证设置路径字符串

        /// </summary>

        /// <param name="path">路径字符串</param>

        /// <param name="isSequential">如果正在创建路径</param>

        static public void ValidatePath(string path, bool isSequential)

        {

            ValidatePath(isSequential ? path + "" : path);

        }

        /// <summary>

        /// 验证设置路径字符串

        /// </summary>

        /// <param name="path">路径字符串</param>

        /// <exception cref="ArgumentException">路径无效</exception>

        static public void ValidatePath(string path)

        {

            if (path == null)

                throw new ArgumentException("路径不能为空");

            if (path.Length == )

                throw new ArgumentException("路径长度必须大于0");

            if (path[] != '/')

                throw new ArgumentException("路径必须启动/字符");

            if (path.Length == ) return;

            if (path[path.Length - ] == '/')

                throw new ArgumentException("路径不能结束与/字符");

            string reason = null;

            var lastc = '/';

            var chars = path.ToCharArray();

            for (var i = ; i < chars.Length; lastc = chars[i], i++)

            {

                var c = chars[i];

                if (c == ) { reason = "不允许空字符 @" + i; break; }

                if (c == '/' && lastc == '/') { reason = "指定的空节点名称@" + i; break; }

                if (c == '.' && lastc == '.')

                {

                    if (chars[i - ] != '/' || ((i +  != chars.Length) && chars[i + ] != '/')) continue;

                    reason = "不允许的相对路径 @" + i;

                    break;

                }

                if (c == '.')

                {

                    if (chars[i - ] != '/' || ((i +  != chars.Length) && chars[i + ] != '/')) continue;

                    reason = "不允许的相对路径 @" + i;

                    break;

                }

                if ((c <= '\u0000' || c >= '\u001f') && (c <= '\u007f' || c >= '\u009F') &&

                    (c <= '\ud800' || c >= '\uf8ff') && (c <= '\ufff0' || c >= '\uffff')) continue;

                reason = "无效的字符 @" + i;

                break;

            }

            if (reason != null) throw new ArgumentException(string.Format("无效的路径字符串 \"{0}\" 引起的 {1}", path, reason));

        }

        /// <summary>

        /// 在目录到客户端的路径（如果有的话）。期望

        ///此功能是客户端路径已在此之前验证

        ////调用/函数调用

        /// </summary>

        /// <param name="chroot"></param>

        /// <param name="clientPath">节点的路径。</param>

        /// <returns>查看服务器的路径（chroot添加到客户端的路径）</returns>

        static public string PrependChroot(string chroot, string clientPath)

        {

            if (string.IsNullOrEmpty(chroot)) return clientPath;

            return clientPath.Length ==  ? chroot : string.Concat(chroot, clientPath);

        }

        /// <summary>

        /// 删除目录

        /// </summary>

        /// <param name="chroot"></param>

        /// <param name="serverPath"></param>

        /// <returns></returns>

        static public string RemoveChroot(string chroot, string serverPath)

        {

            if (string.IsNullOrEmpty(chroot)) return serverPath;

            return string.Compare(serverPath, chroot, StringComparison.Ordinal) ==  ? "/" : serverPath.Substring(chroot.Length);

        }