基于TCP协议的socket编程，实现了客户端与服务器的通信功能，客户端可以登录，向服务器端发送自己要共享的文件的文件名，向服务器发送查找文件请求等。适于socket编程的初学者阅读。-TCP-based socket programming, client communication with the server, the client can log on to the server sending the file you want to share their file name, f