Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watmath!dalcs!iisat!kevin
From: kevin@iisat.UUCP
Newsgroups: comp.unix.xenix
Subject: Re: Does XENIX have sockets?  Also, software availability.
Message-ID: <276@iisat.UUCP>
Date: Sun, 26-Jul-87 15:33:31 EDT
Article-I.D.: iisat.276
Posted: Sun Jul 26 15:33:31 1987
Date-Received: Tue, 28-Jul-87 01:38:52 EDT
References: <114@dalcsug.UUCP>
Organization: International Information Service, Dart., NS
Lines: 34
Summary: Interprocess Communications (IPC)

In article <114@dalcsug.UUCP>, dalegass@dalcsug.UUCP (Dale Gass) writes:
> Does XENIX support interprocess communication through the use of sockets?
> I've found not mention of them, so I assume they don't exist.  What method
> does XENIX use for interprocess stuff such as piping, etc?
> 
> Thanks,
> 
> -dalegass@dalcsug.uucp

No, Xenix does not support sockets as such and I don't think
AT&T Unix does either.  Xenix does support IPC though, using
different routes.

The most common and closest to sockets, is messaging, which is
a "stream" connecting 1 or more processes together. So you can have
1 process send something, and have 3 other ones receiving (like
sockets, once a message is "received", it is deleted from the queue).

Unlike sockets though, you can attach a message type (that you define)
to each message, so that a process which goes to read the message
queue, can receive the first message of a certain type (the type
may be its PID number or something).  Messaging also supports
normal permissions -- owner,group,other (read/write) -- for the queues
providing some security.

Xenix also has semaphores (Xenix version and AT&T) as well as
shared memory (again, Xenix & AT&T versions).

I'm redisigning the "talk" program that was posted a while back from
pipes to messages.
-- 
Kevin Davies		International Information Service (IIS)
UUCP:  {seismo|utai|watmath|garfield} !dalcs!iisat!kevin
----------------------------------------