Dialin/Dialout with specialix board & device mixup. 'exec'ing.

John W. DeBoskey jwd at unx.sas.com
Fri May 25 23:16:16 AEST 1990

   I have two questions, one which I beleive is simple, the other which
may take some thought (I think). Now, some background is in order.

   I'm running ISC 1.0.6 on a PS2 Mod 80. I have a specialix SI/PS8
serial board installed for serial communications. I've been upgrading
to get things to work the way they SHOULD, instead of the kludge that
I've had, and am having trouble.

   The ports on the specialix board have multiple drivers. I use
ttya8 & ttyA8 for instance. 'A' supports HUPCL and blocks on open.
'a' will always open, and doesn't support HUPCL. So what I've done
is run a copy of MODEM (unix src archives) to keep things straight.

   I dial out on ttya8, but accept incoming calls on ttyA8. My init
line looks like:
    ....:respawn:/usr/local/bin/modem ttya8 2400

   Modem goes out to the modem via ttya8 and initializes it and
then waits for an incoming call or a lock file on ttya8. When an
incoming call is recieved, lock files for ttya8 & ttyA8 are created
and modem then spawns a getty on line ttyA8. The login is displayed,
an id is entered, getty execs login, and the user is logged in. 

   Question 1: When I do a 'who' cmd, I see:
                  jwd   ttyA8 
               but if I do a 'ps -ef' I see
                  jwd   ttya8        
               why? How are my process associated with ttya8?

               I have an XT hooked up to one of the ports with
               just a getty on ttyA1 and who & ps show the correct
               device line. What is going on here? Why the internal
               confusion between 'a' & 'A' devices? Every file is
               closed before the execve of getty... Help...

   Question 2: Modem plays with the utmp file to make it look like
               the getty was spawned by init. I understand why. But,
               could someone explain exactly how a process should exec
               another process to take it's place(pid & ppid), but still
               stay active to monitor the child?

   If possible, please respond to jwd at unx.sas.com, and I'll summarize a
   reply after hopefully fixing the problem... Thanks a bunch!!!

                                       John W De Boskey

jwd at unx.sas.com  (w) rti.rti.org!sas!jwd       (919) 677-8000 x6915
jwd at baggins.UUCP (h) mcnc.mcnc.org!baggins!jwd (919) 481-1057 (preferred)

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