I saw with RHEL8 their decision to drop cups using /etc/cups/interfaces files a short time ago which is a big slap for those who need to manipulate resulting application printer output into files or other interfaces for conversion, filing, emailing etc.
Is there a work around as you can’t use:
lpadmin -p printername -i /tmp/scripted_interface -v file://dev/null
or anything similar that I can find. I have to leave Rocky and go back to CentOS 7 to keep this capability which I really don’t want to do if there is something I missed or an additional package that allows this? No use producing a PDF (as in CUPS-PDF) as we need the actual application data produced first.
Went back to CentOS 7 for this issue. Will investigate work-around for this into the future now it has removed this vital feature from application printing by Red Hat.
The problem is upstream cups 2.2 disabled it.
Now RedHat document a work-around at Printing Interface Scripts No Longer Supported in RHEL 8 - Red Hat Customer Portal
it requires a subscription, but you can create a freebie developer subscription to access it.
Basically, to use their example, a “toupper” filter:
cat $6 | tr '[:lower:]' '[:upper:]'
Now create a
*% ToUpper PPD
*Manufacturer: "My Company"
*Product: "(ToUpper Interface Script)"
*cupsFilter: "text/plain 0 toupper"
*cupsFilter: "application/vnd.cups-raw 0 toupper"
*ModelName: "ToUpper Interface Script"
*ShortNickName: "ToUpper Interface Script"
*NickName: "ToUpper Interface Script"
Now define the printer:
lpadmin -p toupper -P ./toupper.ppd -v socket://some_printer/ -E
That should be enough to experiment with and create a similar function to the original.
% cat /usr/lib/cups/filter/tofile
cat "$6" > /tmp/afile
% cat tofile.ppd
*cupsFilter: "text/plain 0 tofile"
lpadmin -p test -P ./tofile.ppd -v file:///dev/null
% enable test
% accept test
% echo This is a test | lp -d test
request id is test-1 (0 file(s))
% cat /tmp/afile
This is a test
Wow, you are an absolute legend. Haven’t seen anything like this out there online and will give it a try and see how it all goes. Thank you so much. Will update you when I get it tested.
I have Fedora 33 as my desktop so has the same limitation - worked first time like a charm. This work-around is just what will keep SystemV type apps alive into the future.
Well done indeed.