POV-Ray : Newsgroups : povray.pov4.discussion.general : On new directive to stop after parsing. A near term trick. : Re: On new directive to stop after parsing. A near term trick. Server Time
23 Jun 2024 08:29:44 EDT (-0400)
  Re: On new directive to stop after parsing. A near term trick.  
From: William F Pokorny
Date: 27 Mar 2024 07:51:10
Message: <6604082e$1@news.povray.org>
On 3/26/24 13:39, Kenneth wrote:
> What is a 'non-zero return code', and what testing problems(s) does it cause
> when using #error? I confess to complete ignorance of it :-/
Hi.

Programs - like POV-Ray - running within typical compute environments, 
return a final integer value called a return code indicating how 
'things' went.

With POV-Ray it's mostly:

0 - All is well.
1 - Some lessor user-ish exit or abort.
2 - Some more serious problem.

But, you can see other non-zero codes too. This more true in yuqk - 
especially the debug compile.


An #error directive will cause POV-Ray to always return (1). Any testing 
looking for "0 - All is well" (or !0), will always see a problem (or 
not) if looking at just the return code(*) where '#error' the technique 
stopping POV-Ray at the parsing stage.

With yuqk, close the X11 preview window with 'q' while the render is in 
progress and you see a return code of (2).

With yuqk, close the X11 preview window, once the render is finished and 
paused, using the 'x' symbol to close and you see a return code of 
(139). Yes, that's a minor bug.

(*) - You can still check how things ran, but without the return code 
giving you the easy answer up front, it means looking at various outputs 
in some detail and checking whether what you expect to be there is, or 
isn't.

Bill P.


Post a reply to this message

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.