Filtering network printers

From: Robert L. McMillin <rlm_at_syseca-us.com>
Date: Mon, 30 Dec 1996 13:46:04 -0800

I would like to add a filter to a networked printer that understands
lpd, in this instance, an Apple color printer. Normally, the printcap
entry for such a device looks like this:

        color:\
                :rm=color:\
                :rp=color:

I would like to preprocess (filter) print jobs to reverse grayscale to
conserve toner, since most of our images have a black background.
However, when I add a 'if=black2white' entry, as

        color:\
                :rm=color:\
                :rp=color:\
                :if=/usr/local/bin/black2white:

lpd doesn't invoke the filter. I have considered the following as one
way out:

        #
        # input filter processes input and redirects via lpr to
        # realcolor spool
        #
        color:\
                :if=/usr/local/bin/black2white:
        
        #
        # black2white filter redirects output to this spool
        #
        realcolor:\
                :rm=color:\
                :rp=color:

I find this offensive. Does the input filter really only come into play
if the printer is local? Does anyone have any suggestions on less ugly
alternatives?

-- 
Robert L. McMillin | Do you *really* think Syseca pays me for these opinions?
     rlm_at_syseca-us.com  | personal: rlm_at_netcom.com | rlm_at_helen.surfcty.com
Received on Mon Dec 30 1996 - 23:15:49 NZDT

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