I'd like to create an FD with O_CLOEXEC.

What would be the most high-level way to do that?

http://hackage.haskell.org/package/unix-2.7.0.1/docs/System-Posix-IO.html#v:OpenFileFlags only gives me append, exclusive, noctty, nonBlock, trunc. What's the idea behind this selection, and can the other flags easily be added?