sync(8) on OpenBSD
The text c0a9e744912d, as OpenBSD 4.9, OpenBSD 4.8, OpenBSD 4.7, OpenBSD 4.6, OpenBSD 4.5, OpenBSD 4.4, OpenBSD 4.3, OpenBSD 4.2 shipped it.
force completion of pending disk writes (flush cache)
The text c0a9e744912d, as OpenBSD 4.9, OpenBSD 4.8, OpenBSD 4.7, OpenBSD 4.6, OpenBSD 4.5, OpenBSD 4.4, OpenBSD 4.3, OpenBSD 4.2 shipped it.
force completion of pending disk writes (flush cache)