[cups-devel] Temporary print queues

[Till Kamppeter]

Hi,

I have some more question about temporary (local) print queues.

1. Print queue auto-creation only works with certain functions of the 
new CUPS API, like cupsGetDest(), but it does not happen when I use 
command line utilities like "lp" or "lpstat". Is this intended?

I would like to have an option for lpstat to also list the discovered 
printers for which there is no CUPS queue (yet) and if I call "lp", 
"lpoptions", "lpstat", ... with the name of such a printer as 
destination name that CUPS creates a temporary queue and executes the 
command instead of giving an error.

2. cups-browsed does not only get the Avahi cache showing the currently 
available printers but also runs Avahi browsers to catch events of 
printers appearing an disappearing, so it always knows which printers 
are available and according to this creates and removes queues. Does 
cupsd also catch Avahi events to remove temporary queues when a remote 
printer disappears?

3. If I start cupsd and then call cupsEnumDests() I get a list of 
available printers, including the DNS-SD-discovered ones. Now I call an 
API function to make CUPS create a temporary queue for a 
DNS-SD-discovered printer. This makes the auto-generated PPD file appear 
in /etc/cups/ppd/. Now I stop cupsd and the PPD is still there. Should 
it not disappear as the temporary queue disappears when CUPS terminates?

I use Ubuntu Zesty with CUPS 2.2.2 but have replaced libcups.so.2 by the 
current GIT state of the art of CUPS (and restarted cupsd, cups-browsed, 
and avahi-daemon).

    Till