基于TCP协议实现客户端与服务器在约定的端口上进行数据传输。客户端程序仅知道服务器的主机名，并不知道服务器的IP地址。

客户端

1从命令行输入服务器的的主机名连接到服务器；

2获取本机的相关信息包括：IP地址、开通的端口、操作系统的名称、本机名称列表、操作系统版本号、硬件版本；

3将上述信息进行凯撒加密并发送给服务器；

4接受服务器返回的经处理后的字符串，并显示；

5当用户输入CTRL+D或者“bye”时终止连接并退出。

服务器端

1服务器等待客户连接，连接成功后向客户发送欢迎信息；

2接收该客户的信息，然后解密并显示，并将收到的客户端操作系统版本号信息送回给客户端；

3要求服务器具有同时处理多个客户的能力。-TCP-based client and server to achieve the agreed port for data transmission. Client only know the server s host name, do not know the server s IP address.

Clients

A command line, enter the server s host name to connect to the server

2 to obtain the relevant information, including the machine: IP address, open ports, operating system name, local name of the list, operating system version, hardware version

3 Caesar the above information is encrypted and sent to the server

4 Accept the server returns the string after treatment, and display

5 When the user enters CTRL D or "bye" to terminate the connection and exits.

Server-side

1 server waits for client connections, the connection is successful to send welcome message to the customer

2 receives the customer information, and then decrypt and display, and will receive the client operating system version information back to the client

3 requires that the server has the ability to simultaneously handle multiple clie