sendfd can be used to pass an open file descriptor over
a Unix domain socket from one process to another.
is implemented with
socket can be a file descriptor obtained from
Sendfd sends the file descriptor
fd along the socket to a process calling
recvfd on the other end.
It is assumed that the two sides have coordinated
and agreed to transfer a file descriptor already, so
sendfd is met with a
recvfd instead of an ordinary
The file descriptor number may change on its way
between processes, but the kernel structure it represents