网络协议之ftp---ftp 协议详解

http://blog.csdn.net/yxyhack/article/details/1826256

http://blog.chinaunix.net/uid-7777486-id-2043939.html

http://www.w2bc.com/Article/16397

http://www.ibm.com/developerworks/cn/linux/l-cn-socketftp/

http://www.codeforge.cn/read/171547/ftpclient.c__html

http://www.elecbench.com/?p=1077