Using rev with -ui flag
J. Landman Gay
jacque at hyperactivesw.com
Tue Jan 13 15:57:16 CST 2009
Ben Rubinstein wrote:
> I have a number of questions - answers to any or
> all would be gratefully received, as would any other relevant
> observations or suggestions.
> * Is the -ui flag documented anywhere? I can only find references from
> users on various forums and lists - nothing from RR
I thought it was mentioned in the engine change log when it first
appeared but now I can't find it. Mark Waddingham has confirmed that
it's what to use in some posts on the improve list, I think. At any
rate, I know it's the official "right way" to do it.
> * Evidently the -ui flag implies don't start the GUI; does it have other
Not that I know of.
> * Is there a way for a stack to tell that it's in "-ui" mode? The flag
> doesn't appear in the $0, $1 etc globals
The "environment" variable will be "command line". That isn't documented
either; I found out by testing.
> My app already has an "unattended" mode in which it is invoked from the
> command with some additional parameters, and then (although still
> normally displaying the UI) it goes through a sequence automatically,
> and then automatically quits. I expect it also to write some note to
> stderr. Launching this with the -ui option it is totally silent, and it
> does not appear to do anything, nor does it quit. I've made a minimal
> stack that just writes some notes to the console and then quits - that
> works as expected in the -ui mode. I'm guess that this means that my
> real app is doing something during startup which is illegal in -ui mode;
> therefore it throws an error and never gets to write anything to console
> or to quit.
If there's a problem, it should show up in the error log.
> * Are there known gotchas, things that you mustn't do in -ui mode?
Not really; some gui-related things won't work but you'll usually get an
error in that case. Most things behave as you'd expect.
From my CGI tutorial:
Some native Revolution commands that don't work (and may hang your
* go - requires a GUI window redraw
* toplevel - GUI-based
* modeless (or any other stack modes) - GUI-based
* create stack (or any file creation) - CGI permissions restriction
* save stack (errors with "can't open stack backup file") -
* beep - GUI-based
Jacqueline Landman Gay | jacque at hyperactivesw.com
HyperActive Software | http://www.hyperactivesw.com
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