得到recv函数的缓冲len。

I wrote a simple FTP application that can send files back and forth between a client and a server and it was working fine. More recently I wrote a socket library to use with the client and server, some of the functionality has changed, and I'm having trouble wrapping my head around how to get it to work. At the moment I'm integrating the library on my server. I wrote a simple FTP application that can send