Sure, there's a way to tell. There are lots of ways of telling which platform you're on (#defines), and platforms can document the expected behavior. If a pla

Sure, there's a way to tell. There are lots of ways of telling which platform you're on (#defines), and platforms can document the expected behavior. If a platform doesn't, then complain to the vendor. Yes, it sucks to resort to conditional compilation around "close", but it's already been explained why it's necessary. POSIX was not created in a vacuum as a theoretically ideal OS specification.