System V communication facilities query

[Guy Harris]

> Can anyone feed me some information on the interprocess communication 
> facilities that are available with System V - ie what is the equivalent of
> the BSD 4.2 socket on Sys V? I believe there exists an equivalent facility,
> called "streams", but that's about as much as I know.

There is no equivalent facility on System V as it comes from AT&T.  It has
an IPC message mechanism that only works between processes on the same
processor.  A facility based on I/O connections called "streams" was
developed by Dennis Ritchie as part of "Eighth Edition" UNIX (which is based
on 4.1BSD).  This is described in the latest UNIX edition of the AT&T Bell
Laboratories Technical Journal (October 1984, Vol. 63 No. 8 Part 2), but it
doesn't go into much detail about the networking aspects of streams (i.e.,
how do you specify a protocol, how do you connect to a given port on a given
remote host with a connection-oriented protocol, how do you send a packet to
a given port on a given remote host with a connectionless protocol, how do
you specify routing, etc.).  AT&T has made some statements that a networking
mechanism based on streams will be available in a future System V release.
They haven't said to what degree it resembles the streams mechanism in
Eighth Edition UNIX, nor have they given any more details about that
mechanism beyond what's in the BLTJ.

	Guy Harris