On Apr 23 16:25, qq qq wrote: > The following code is a simplified app that was used to test-connect > to local ports 55000+ (none of which were actually listening) and > received false-positive "connected" results because Cygwin's dup() > for socket causes SO_ERROR to be lost.  Since FD_SETSIZE is only 64 on > Cygwin, the app uses dup()'s to lower the descriptors as it checks > them for completion.  There is no such problem on Linux. > Also, strangely that Cygwin does not accept sin_addr as 0 to connect > locally (and either localhost or local host IP must be stuffed in > there, otherwise resulting in the "Cannot assign requested address" > error). This is Winsock at work. Cygwin doesn't check the AF_INET address when calling Winsock's connect, so Winsock's connect itself seems to have this issue. As for the SO_ERROR value, I have to check. Thanks for the testcase. Corinna -- Corinna Vinschen Please, send mails regarding Cygwin to Cygwin Maintainer cygwin AT cygwin DOT com Red Hat