my server program is writed with c in windows using mingw,using "select" model client is writed with python the problem is , when the client connect the server, the function FD_ISSET(cilentfd,&set) always true, but it hvae read no data, i also no send data to server. why? i use telnet program in windows to test my server ,it good ,FD_ISSET is work ok, it return false