title: What non-Linux unixes support openat()?
body: <p><a href="http://linux.die.net/man/2/openat" rel="noreferrer">openat()</a> was added to POSIX in the POSIX.1-2008 revision, and has been supported by Linux since 2.6.16. How is support on non-Linux UNIXes? eg, Darwin, the *BSDs, and proprietary UNIXes.</p>