DotNet处理服务器路径的方法

项目中需要使用到路径处理的地方比较多，对于路径的解析和匹配有时较为繁琐，现在提供一个对路径进行解析的方法：

1.验证设置路径字符串：

        /// <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));
        }

2.查看服务器的路径：

        /// <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);
        }

3.删除目录：

        /// <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);
        }