[comp.unix.wizards] Help needed with slave terminals

og@litp.UUCP (05/13/87)

	I work under UNIX 4.3bsd. I want to use a terminal as  a slave
terminal. Say the master terminal is M and the slave is S. I need some
of the output produced by a program running on M to be routed to S and
I need that program to take some of its input from S.

	Now the problem I have  is  the following:  terminal S is  not
hardwired and cannot be hardwired.  So  it's a  plain regular terminal
that can only gain access to the system via login. This implies that a
shell is running on it. Thus it's allright to send  data to it, but if
I type something on its keyboard what I type will be picked  up by the
shell running  on S   rather than by  the program  I'm  running  on  M
eventhough its awaiting input from S. 

	I suspect the solution lies in pseudo-terminals  (pty's) but I
don't quite get how the whole thing works. The manual page is somewhat
cryptic to me. What I need  in  fact is some  program or suggestion of
program that I could run on S and that could make it become a slave.

	For  those who know  Multics  I  want the  equivalent of   the
"slave" command you can give at dialup time instead of "login".
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weil@dataio.UUCP (05/15/87)

Simple, we do this all the time for developing screen oriented software.
On the slave terminal simply run a small program which closes stdin
and stout and sleeps forever.  (If you need, you can also set it up to 
ignore interrupts.)

Then any other program may open /dev/ttyxx and read and write from/to this
terminal.