[mod.computers.vax] Debugging screen management progs

STEINBERGER@SRI-KL.ARPA (Richard Steinberger) (10/24/86)

Have you ever tried to use the symbolic debugger to trap bugs in programs
that make calls to the SMG$ routines?  It's not all that useful because,
alas, the screen output is disturbed.  What I would like to do is
have the debugger get its I/O from a different terminal than where the 
'screen mode' program is running.  Does anyone know how to do this?
Are there better ways to debug 'screen mode' programs?  Thanks for the
help.

Ric Steinberger
STEINBERGER@SRI-KL

(415) 859-4300


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cetron%utah-ced@UTAH-CS.ARPA (Ed Cetron) (10/24/86)

I seem to recall that debug input comes from dbg$input and that
it can be redirected if you so desire....this is also useful for
detached processes which specifically have no sys$input or sys$output...

-ed

DEGROOT@HWALHW5.BITNET (10/24/86)

        >Subj:  Debugging screen management progs
        >
        >From: Richard Steinberger <STEINBERGER@SRI-KL.ARPA>
        >Subject: Debugging screen management progs
        >
        >Have you ever tried to use the symbolic debugger to trap bugs..
        >that make calls to the SMG$ routines?  It's not all that usef..
        >alas, the screen output is disturbed.  What I would like to d..
        >have the debugger get its I/O from a different terminal than ..
        >'screen mode' program is running.  Does anyone know how to do..
        >Are there better ways to debug 'screen mode' programs?  Thank..
        >help.
        >
        >Ric Steinberger
        >STEINBERGER@SRI-KL

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One of the VAX/VMS manuals titled 'Utility Routines Reference Manual'
(the VMS 4.3 set) contains a description of PSM Print-Symbiont Routines.
Page PSM-16 tells you how to debug a user-written symbiont.
The trick is to DEFINE/GROUP DBG$INPUT and DBG$OUTPUT to TTcu:.
I am currently working on a modified symbiont and the trick does work.

Tel. +31-8370-  .KeesdeGroot    (DEGROOT@HWALHW5.BITNET)  o\/o  THERE AINT NO
     (8)3557/   Agricultural University, Computer-centre   []   SUCH THING AS
        4030    Wageningen, the Netherlands               .==.  A FREE LUNCH!

DISCLAIMER: My opinions are my own alone and do not represent
            any official position of my employer.

cspencer@CC5.BBN.COM (10/24/86)

> Have you ever tried to use the symbolic debugger to trap bugs in programs
> that make calls to the SMG$ routines?  It's not all that useful because,
> alas, the screen output is disturbed.  What I would like to do is
> have the debugger get its I/O from a different terminal than where the 
> 'screen mode' program is running.  Does anyone know how to do this?
> Are there better ways to debug 'screen mode' programs?  Thanks for the
> help.

I have had a different problem when attempting to debug
SMG$ programs. I get an error about "pasteboard already
in use" and the debugger exits. Can anyone suggest how
to sidestep this? 
						-cliff