I am trying to set up a CUPS printer that will print a single print
job on two separate printers. I saw a technique online using a CUPS
interface script, but when I set it up it seems the interface script
is being by-passed when I send a job to the printer.

The method I found and am trying to use is to create a printer with
the URI set to /dev/null and define an interface on that same printer
that spawns two new print jobs, one to each of the two printers I want
it to print on. Here is what I have done:

Created interface_script:

#!/bin/bash
echo "Interface script is running." >>/home/me/debug
/usr/bin/lp -d printer1 $6
/usr/bin/lp -d printer2 $6
_________________________________

Created Printer:

lpadmin -p twoprint -i interface_script -v /dev/null -E

The lpadmin copies the interface_script into /etc/cups/interfaces/twoprint
as expected and the permissions on the twoprint script are 755. The CUPS
LogLevel is set to debug2 and I don't see anything that looks to me to be
an obvious problem in /var/log/cups/error_log after I send a print job to
twoprint.

Does anyone have an idea why the twoprint interface script is not getting run?

Have you verified the new printer does not show any errors and is enabled? Have you checked the jobs to see if anything is stuck in the queue?

With a similar set up that I had already had but using a real printer i.e. instead of /dev/null I used ipp://localhost/printers/myprinter and a interface script it worked for me.

The next step is to create a null printer to duplicate your exact configuration.

Ok I duplicated your setup and it worked for me.

What distribution/version are you running?

michaelk,

Thank you for working on my problem and for your reply. The fact that you were able to get it to work pushed me to keep trying. I eventually figured out what I was doing wrong and it was not in the set up - it was in the lp command I was using to send the original job to the printer. Being fairly new to linux, I used lp command options I had seen used other places without really looking into what they do. I was using the -o raw option which, as I now understand, tells cups to not execute any interfaces/filters. I sure feel stupid right now. When I enter the lp command like this the job prints on both printer1 and printer2:

lp -s -d twoprint filename

Thanks again for setting it up yourself and getting it to work.

Your welcome.

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