Unix Domain: Unix and UDG
unix://
and
udg://
.
unix:///tmp/mysock
udg:///tmp/mysock
unix://
provides access to a socket stream
connection in the Unix domain. udg://
provides
an alternate transport to a Unix domain socket using the user datagram
protocol.
Unix domain sockets, unlike Internet domain sockets, do not expect
a port number. In the case of fsockopen() the
portno
parameter should be set to 0.
Note: Unix domain sockets are not supported on Windows.