[cups.development] Filter - backend communication example?

[Helge Blischke]

Michael Sweet wrote:

> On Feb 5, 2010, at 7:52 AM, Paul Newall wrote:
>> ...
>> Update 5/feb/2010:
>> I cut my filter right down to a minimum and called it directly in the PPD
>> file: *FoomaticRIPCommandLine: "myminifilter %A"
> 
> OK, if you are wrapping your driver in Foomatic you're going to run into
> problems like these. Real CUPS drivers should NEVER use Foomatic, which is
> just (and should remain) a wrapper for existing Ghostscript drivers and
> tries to support multiple spoolers (not just CUPS) which means it has
> trouble supporting all of the CUPS printing functionality.
> 
> ___________________________________________________
> Michael Sweet, Senior Printing System Engineer

I think what is needed is that the backend flushes the output to the 
printer, but the fflush(stdout) in the filter only flushes the pending stuff 
to the backend only (if the filter is wrapped by foomatic or not).

Helge