PPD or backend?

[Erik de Castro Lopo]

Hi all,

For a couple of years now I've been using a small APS brand
printer that connects via serial port. In order to support this
printer, there is a binary executable (i have GPL sources as
well) that gets installed at /usr/lib/cups/backend/aps as will
as a Postscript Printer Description (PPD) file that gets installed
under /usr/share/cups/model/ (which gets copied to /etc/cups when
the printer is configured).

Working with this printer has been relatively straight forward
and from a program that uses the CUPS API I can detect if the
printer is present, whether it has paper, whether its nearly
out of paper etc.

I am now working with a new printer (by Zebra) which connects
via USB. All that this printer seems to require is a PPD file,
but using the PPD, the CUPS API can't even tell me if the
printer is connected.

So, my question is, can a printer that only requires a PPD file
give me feedback like presence, paper status etc or do I need
to write a CUPS backend driver to get those features.

TIA,
Erik