For some reason lately, I have been running into an obscure, undocumented system variable that is wrecking havoc on certain AutoCAD commands, or so it may seem. Some of you may have heard of QAFLAGS. I first ran across it years ago at manusoft.com, where Owen has provided documentation (not sure if that is his own description, or something originally from Autodesk…). The default value is 0. I’ve been using it for years to bypass the pause in text screen listings (bitcode 2).
Note that because it is a bitcoded system variable, you can set it to any valid value such as 384 (128+256), 1538 (1024+512+2), 32767, etc., however the effects of these other bits are undocumented, if they do anything at all.
Below I will attempt to document other known effects. I run across these just infrequently enough to forget them in the meantime, so now I’ll have a reference.
- If bit 1 is set and you execute certain commands while objects are selected and gripped, the selection is canceled and the grips vanish. ._Copyclip is one of these commands.
- In Autolisp, if you preselect some items using (sssetfirst) and wish to explode them using the ._Explode command, you will need to set bit 1 of QAFLAGS, otherwise the selection is canceled before the command executes (this may be AutoCAD version specific). Some more information on QAFLAGS and Explode can be found in this discussion thread at the AUGI forums.
- If you are calling the ._Copy command using Autolisp and QAFLAGS = 0, then the copy command will operate in single copy mode. If bit 1 is set, it will operate in multiple copy mode.
Here is a post from the Mistress of the Dorkness on QAFLAGS, and lastly, here is some good information on command versioning that can be used instead of the QAFLAGS trick in certain situations.
Please leave a comment if you have run across something I have missed.
