I guess this isn't the best place to ask this question, but I think there are knowledgeable people here. I don't know the right place, so I'd welcome being redirected to a better one.
The POSIX spec for close() is here: https://pubs.opengroup.org/onlinepubs/9699919799/ This specification has a lot of cases that explicitly apply only to the last close of an object, either using that language or by saying that something happens when "all file descriptors associated with" an object are closed. But it doesn't say that for sockets. Instead, it just says, "If fildes refers to a socket, close() shall cause the socket to be destroyed," which implies that closing any file descriptor for a socket destroys the socket. I think that must be wrong, because I don't think that's the behavior on the systems I've used. Do I misunderstand the spec? Or the behavior on real systems? (Should I submit a request for clarification to the spec maintainers?) Thanks, Ben.
