[cups.general] How to get a class to support duplexing?

[Johannes Meixner]

Hello,

On Feb 24 08:54 Michael Sweet wrote (shortened):
> ... the cupsGetPPD API will get the PPD for
> the first printer in the class

How exactly is "the first printer" in a class defined?
Is it perhaps the topmost "Printer" entry in classes.conf
or is it perhaps a random printer in the class depending
on whatever it gets first at a particular time?


A related question:

Assume there are two printer devices with different capablities
so that neither the capablities of the first are a subset of
the second nor the capablities of the second are a subset
of the first (e.g. only the first printer supports duplex
while only the second supports color).

Nevertheless the user likes to have both in a
class "simplex_monochrome".

If printers with different capablities are in a class
the PPD for the class should contain the intersection
of the capablities of all printers in the class.

Would it work to set up a "virtual" queue which does
not accept print jobs and additionally printing is stopped
with a device URI file:/dev/null and a selfmade PPD which
contains the intersection of the capablities of both printers
and have this queue as topmost "Printer" entry in classes.conf
so that the virtual queue is never used for actual printout
but cupsGetPPD will get the right PPD for this class?


Do you think it makes sense for a feature request
that it is possible to assign a PPD to a class like

   lpadmin -p queue_name -c class_name -P /path/to/file.ppd

so that cupsGetPPD will first try to get /etc/cups/ppd/class_name.ppd
and use the PPD for the first printer in the class as fallback
when no /etc/cups/ppd/class_name.ppd exists?



Kind Regards
Johannes Meixner
-- 
SUSE LINUX Products GmbH, Maxfeldstrasse 5, 90409 Nuernberg, Germany
AG Nuernberg, HRB 16746, GF: Markus Rex