Filer order.

[Dyna]

Hi Micheal,

Thanks for the answers! Have a few questions to follow up with, please see below.

On Sep 18, 2009, at 4:31 PM, Michael Sweet wrote:
> On Sep 18, 2009, at 2:11 PM, Dyna wrote:
> > *cupsFilter: "application/vnd.cups-postscript 0 toGray"
> >
> > Well it does execute the filter but not first and surly not last
> > either (or at least it doesn't look like it).
>
> It generally will be the last filter before the backend; the only
> possible filter between it and the backend would be the port monitor
> which has to be explicitly configured.

May I ask where I can get info about the port monitor? There is a few lines in the "PPD File Syntax" page. But it looks more to be about monitoring the printer i.e. that its up and running or not.


> If you want to be the first filter for a format, use the cupsPreFilter
> keyword in the PPD file.

I was looking at that but the in the printers.conf listing it as a 1.4 only option. In the "PPD File Syntax" page cupsPreFilter is listed as 1.3 and above option. I assume this is not a typo and I can use cupsPreFilter  with the cups 1.3.9 I'm currently running.

Now, it makes me asking what do you need to specify in the printers.conf? What good does the filters do in printers.conf. Sorry it might be a silly question.

Anyways big thanks for all the help so far, makes my day a happy day, since I'm one step closer to print in high speed GrayScale on my slow Color Laser printer :). toGray is simply a little ps2write filter..


> The order of filters is defined by their input and output formats,
> along with the source and destination formats.  For example, if you
> print a PDF file on Linux to a printer with your PPD file, you'd see
> the following filters get run:
>
>      pdftops | pstops | toGray | backend

Thanks for that one it makes it a lot easier to understand!

Cheers Dyna