[Info-vax] Reopen OPERATOR.LOG from batch?

[Jon Pinkley]

On Thursday, September 5, 2019 at 1:16:25 PM UTC-4, Simon Clubley wrote:
> I think Jan-Erik has probably worked out what that command does already, :-)
> but the real question is _why_ does it make a difference ?
> 
> The answer appears to be that reply/enable checks whether it is running
> in a batch job by checking whether the current input device is a terminal
> or not.
> 
> Unless that behaviour is documented as supported, it seems to me
> that behaviour is prone to breaking if someone changes the code to
> check in the proper way for whether the command is being run in a
> batch job.
> 
> Question: Can you start up a scripted pseudo terminal session from
> within a program running in a batch job (I've never tried it) and
> if so, will the pseudo terminal session appear as an interactive
> session or as a batch session ?
> 
> If it's the former, that might be a supported way for Jan-Erik to
> do this.
> 
> Simon.
> 
> -- 
> Simon Clubley, clubley at remove_me.eisner.decus.org-Earth.UFP
> Microsoft: Bringing you 1980s technology to a 21st century world

Using a pseudo terminal may be "supported", but it would definitely be a Rube Goldberg solution compared to the 4 line method.

The method used, define/user, has worked from long before pseudo terminals even existed on VMS. And it is documented, for example, in the OpenVMS System Manager's Manual.

https://www.itec.suny.edu/scsys/vms/ovmsdoc073/v73/6017/6017pro_003.html

see section "2.4.5 Designating Operator Terminals"

"To designate an operator's terminal in batch or in startup command procedures, SYS$COMMAND must be assigned to a valid terminal device."

The use of "reply/log" to open an new version of the log file is a rather esoteric.

If VSI ever breaks it, they should create another way or api to comminicate directly with OPCOM.