Using rev with -ui flag

[Ben Rubinstein]

I'mn trying to get to grips with an app that's going to have to run on a 
headless Linux box.  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

* Evidently the -ui flag implies don't start the GUI; does it have other 
implications?

* 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

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.

* Are there known gotchas, things that you mustn't do in -ui mode?

Many thanks in advance,

Ben