wb6rqn@yojna1.UUCP (Brian Lloyd) (11/07/85)
*** REPLACE THIS LINE WITH YOUR INSIPID BLATHERING *** I have a stream of data coming in on a standard TTY port. This stream consists of several multiplexed TTY sessions. I need to demux this stream (not a problem), and feed the demuxed outputs to several pseudo TTYs (a problem). On the other side, I need to take the streams from the pseudo TTYs, multiplex them into a single stream, and send it out the standard TTY. I need all the standard UNIX utilities to run from a pseudo TTY. 1. Is what I want to do possible in UNIX SysV? 2. How do I make use of pseudo TTYs? 3. Does anyone have any sample C code that does anything like this? Thank you in advance. Brian Lloyd ...![bellcore|cp1]!yojna1!wb6rqn
gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (11/08/85)
> I have a stream of data coming in on a standard TTY port. This stream > consists of several multiplexed TTY sessions. I need to demux this stream > (not a problem), and feed the demuxed outputs to several pseudo TTYs (a > problem). On the other side, I need to take the streams from the pseudo > TTYs, multiplex them into a single stream, and send it out the standard > TTY. I need all the standard UNIX utilities to run from a pseudo TTY. This is what the "sxt" pseudo-devices are designed for (Release 2.0). There are no real ptys on any UNIX System V that I have seen, although they would be a natural for stream I/O-based releases such as are expected someday.. Note that your situation is similar to that of the DMD (aka Blit); AT&T provides an "xt" driver with the DMD software. However, the "xt" driver is DMD-specific and therefore probably not suitable without major hacking.
ron@BRL.ARPA (Ron Natalie) (11/09/85)
Actually, the way the System V terminal driver is set up, it is designed to help you do this. Unfortunately, it means driver hacking, and you really do need a UNIX source license. If you can find one, look at the xt.c driver for running the BLITs and tty5620 terminals, it is switching a packetized input stream consisting of six virtual terminals into separate xt000 devices. System V doesn't really have pty's at all. The SXT (which are VR2 anyhow) devices are a kludged up version of the code for the xt driver. What they do is switch a single real tty line back and forth between a set of virtual terminals. Doing this, they achieve something roughly equivelent to the 4.2 Job control. The difference is that you actually have a shell on each of the sxt virtual devices. What you are really doing is switching your real tty to several virtual tty "contexts." -Ron
wb6rqn@yojna1.UUCP (Brian Lloyd) (11/13/85)
> Actually, the way the System V terminal driver is set up, it is > designed to help you do this. Unfortunately, it means driver > hacking, and you really do need a UNIX source license. If you > can find one, look at the xt.c driver for running the BLITs and > tty5620 terminals, it is switching a packetized input stream > consisting of six virtual terminals into separate xt000 devices. > > System V doesn't really have pty's at all. The SXT (which are VR2 > anyhow) devices are a kludged up version of the code for the xt > driver. What they do is switch a single real tty line back and > forth between a set of virtual terminals. Doing this, they achieve > something roughly equivelent to the 4.2 Job control. The difference > is that you actually have a shell on each of the sxt virtual devices. > What you are really doing is switching your real tty to several virtual > tty "contexts." > > -Ron *** REPLACE THIS LINE WITH YOUR MESSAGE ***