Unable to print to USB

[Timetrinus]

>
> Hello,
>
> On Feb 23 06:55 Timetrinus wrote (shortened):
> > ... kernel: ... usbfs: interface 0 claimed by usblp
> >                 while 'usb' sets config #1
>
> You cannot have two different drivers (kernel modules)
> talking to the same USB device. In this case usblp
> and usbfs (ie: libusb).
>
> It should help to unload the usblp kernel module.
>
>
> > device for Test: usb:/dev/usb/lp1
> ....
> > cups	1.4.2-9
>
> Since CUPS 1.2 the old style USB DeviceURI "usb:/dev/usb/lp*"
> is no longer allowed. Only the new style USB DeviceURI
> "usb://<make>/<model>?serial=<number>" can be used because
> only this kind of URI works for more than one USB printer.
> The old style URI can permute which printer is accessed
> via which /dev/usb/lp* device node depending on the sequence
> how the printers are switched on.
>
> It should help to use exactly the DeviceURI as it is reported
> by the CUPS usb backend (to let the CUPS usb backend report
> the DeviceURI, run it as root without parameters e.g. like
>    root at host# /usr/lib/cups/backend/usb
> or run as root CUPS' "lpinfo -v" command e.g. like
>    root at host# lpinfo -v
>

That's a great info. Thank you. I have already seen lpinfo -v but it has taken very long. My problem is that I have to implement a mechanism that automatically configures the attached USB Printer for a special queue with a fixed defined name. If no USB Printer is connected or the user disconnect it this queue has needs to be reconfigured so it uses the pdf backend.

In many distros usb printers are configured automatically by system-config-printer-udev. I tried to understand the code but I don't. So the hint with /usr/lib/cups/backend/usb is wonderful! I can parse the output and work with it.

One little more question: I have seen that hp printers are handled differently from this behaviour. Does it work with these printers too? Are there any other vendors that are also handeld differently?

Thank you!