说明：  一个简单的文件传输，传输的是RAR格式的文件，适合比较大型的文件传输利用windows socketC语言编程的，比较是在VC下的控制台环境下编译的。
(A simple file transfer, transmission is the RAR file format, suitable for relatively large-scale file transfer using windows socketC language programming, the comparison is in the VC console under the circumstances of the compiler.)