[mod.computers.vax] Symbionts

iwm@doc.ic.ac.uk (Ian Moor) (05/29/86)

I am trying to produce a symbiont to interface to various machines over
our LAN - an IBM, Unix etc talking various protocols. In all cases I have
programs already running that do the work of the transfer (kermit etc).
The problem is debugging the symbiont - written in Pascal. Symbionts run
with all of SYS$INPUT, SYS$OUTPUT, SYS$ERROR and SYS$COMMAND directed to
JOB_CONTROL, when my symbiont crashes it sends a backtrace to SYS$ERROR,
JOB_COTROL reports the 'unexpected message' BUT DOESNT SAY WHAT IT IS!
and the crashes when it gets an EOF from the symbiont. I have to restart 
all of the queues, and once lost the queue file. I have tried catching
the error using an exception handler, which works sometimes, but would
like to know how to redirect the error messages reliably. Does anybody have
a test harness for symbionts (which is more reliable than JOB_CONTROL!).
--- Well at least the interface is documented in VMS 4.