Domain Socket

[David Grubbs]

In article <1991Jan27.023818.4112 at cs.mcgill.ca> tinyguy at cs.mcgill.ca (Yeo-Hoon BAE) asks:

   This may not apply to the A3000UX, but what exactly is the
   'Domain socket'? I think it's only supported by Berkerley Unix.
   Thanks.

All sockets are "Domain sockets".  The question is *which* domain.  Most
programmers use sockets in the "TCP Domain" because they work both on the
local machine and across networks.

But there are other Domains.  If you have the kernel support, there is a
socket domain available for each major networking type: XNS, ISO (though it is
handled strangely), SNA (even more strangely) and what is called the "Unix
Domain socket", to which I believe you refer.

A "Unix Domain Socket" is one which expects only to talk to processes on the
local host.  In the latest Berkeley code, a "pipe()" (invoked by using '|' in
the shell) is a unix domain socket pair.  Last time I looked, X11 allowed you
to use "unix:0.0" as a DISPLAY name and it would create Unix domain sockets
instead of the default TCP domain sockets.

Unix Domain sockets generally incur much less overhead than other kinds of
sockets, generating somewhat less "system time".

If you want to understand Amiga Unix, starting reading about Unix.
--
David G. Grubbs				Kendall Square Research Corp.
{harvard,uunet,world}!ksr!dgg		dgg at ksr.com