See also: <a href="https://news.ycombinator.com/item?id=19836673" rel="nofollow">https://news.ycombinator.com/item?id=19836673</a><p>Instead of pidfd_send_signal I would have wanted to have PIDFD_OFFSET, which if you add a file descriptor (from a process's directory in /proc) to that constant you can use it wherever a process ID is expected.