I'll add the following sentence to socket-close;

The procedure should not shutdown the given socket. To shutdown a
socket, socket-shutdown should be called explicitly.

This is my curiosity. I think most of platforms free fd when close(2) is
called and means the given socket fd will be invalid. What would be the
happy case that socket-close doesn't automatically shutdown the socket?

_/_/
Takashi Kato
E-mail: xxxxxx@ymail.com