[cups.general] PPD generation on the fly

Johannes Meixner jsmeix at suse.de
Tue May 30 07:15:56 PDT 2006


Hello,

from a printer manufacturer I got the following information
(at the moment anonymized)
------------------------------------------------------------------
"ACME PrintSystem" is developed with the purpose of providing
a general purpose, model independent driver.
To this end, the driver queries the printer directly for its
capabilities and creates an optimized PPD file based on the
printer's reply.  
This way it is no longer necessary to download and install
drivers when the user changes or adds new printers.
------------------------------------------------------------------

For me this is a new concept which seems to be not in compliance
how printer setup works in CUPS because as far as I know this
requires ready-made PPD files in /usr/share/cups/model/
(more exactly in "echo $(cups-config --datadir)/model/").

I would like to know what you think how it could work in
compliance to the usual printer setup in CUPS.

Something which I have in mind up to now:

1.
Use a postinstall script in the RPM for this driver
which runs the driver and creates the PPD file.
Drawbacks:
Doesn't work if the printer is not connected while
the RPM is installed.
Doesn't work when the user changes or adds new printers.

2.
Use a special backend and let this backend autodetect
the printers which are supported by this driver and for
each autodetected printer let the backend run the driver
and create the PPD file.
Drawbacks:
Normally a backend is not allowed to create files
in /usr/share/cups/model/ (except it runs as root).
At the moment I don't know if cupsd runs the backends first
and then scans /usr/share/cups/model/ for new PPD files
or vice versa.

3.
This driver seems to cause the same problems as using the
Foomatic setup tool when it creates the PPD on the fly
from XML sources instead of using ready-made PPDs.
Is there a solution for this problem?


Kind Regards
Johannes Meixner
-- 
SUSE LINUX Products GmbH, Maxfeldstrasse 5      Mail: jsmeix at suse.de
90409 Nuernberg, Germany                    WWW: http://www.suse.de/





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