unlink(1) is indeed in SUSv2/XCU5: http://pubs.opengroup.org/onlinepubs/7908799/xcu/unlink.html http://pubs.opengroup.org/onlinepubs/7908799/xcu/unlink.html I

unlink(1) is indeed in SUSv2/XCU5: http://pubs.opengroup.org/onlinepubs/7908799/xcu/unlink.html http://pubs.opengroup.org/onlinepubs/7908799/xcu/unlink.html I couldn't get my hands on SUSv1/XCU4. It's supposedly available here: https://publications.opengroup.org/c43x https://publications.opengroup.org/c43x But you have to log in to download, and I gave up upon seeing account creation form with 16 required fields. "Open" in "The Open Group" is a bad joke.