Managing subprocesses running a shell

Mark Benard mb at rex.cs.tulane.edu
Fri Feb 10 14:58:58 AEST 1989


I am trying to design a package (for students to implement and modify) to
manage one or more shell processes at a single terminal under 4.3bsd
(actually Pyramid's OSx 4.4).  I have tried pipes and pseudo terminals for
communicating with a shell running as a subprocess to a server, but I am
having problems.  Primarily the problem is that the server and the process
group gets stopped because of tty input (because they are treated as
background processes ?), but even when I keep the processes from stopping, I
get very little output from the the shell and no evidence that the shell is
getting the input.  (I am communicating directly to the 'server' from
a terminal.)

I am not familiar with the internals of windowing packages, but I assume that
they do things similar to what I want.  Can anyone point me in the right
direction?  (I am not concerned about the terminal display at this point,
just the process communication and synchronization.)

The problems I am having seem to be related to the fact that I am running
a subprocess which is execing a shell (tcsh), since I can communicate
ok using psuedo terminals if I exec an ordinary program in a subprocess.
However, in this case, I still have the problem of 'prompts' (lines
not terminated with a newline) not appearing until a newline is sent
to the output psuedo terminal.

Any help would be appreciated.
-- 
Mark Benard
Department of Computer Science     INTERNET & BITNET: mb at rex.cs.tulane.edu
Tulane University                  USENET:   pyramid!rex!mb
New Orleans, LA 70118



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