Subject: pkg/24108: ...pkgsrc/print/ghostscript-gnu emits garbage into print output. (workaround)
To: None <email@example.com>
From: None <firstname.lastname@example.org>
Date: 01/15/2004 07:11:20
>Synopsis: ...pkgsrc/print/ghostscript-gnu emits garbage into print output. (workaround)
>Arrival-Date: Thu Jan 15 13:12:00 UTC 2004
>Originator: Richard Rauch
>Release: NetBSD 1.6ZG
"I probably don't know what I'm talking about." http://www.olib.org/~rkr/
System: NetBSD socrates 1.6ZG NetBSD 1.6ZG (socrates) #1: Wed Dec 31 15:24:34 CST 2003 root@socrates:/usr/netbsd/current/src/sys/arch/amd64/compile/obj.amd64/socrates amd64
I set up MS-WINDOWS '98 on another machine and had it talking
to my NetBSD machines via samba. I set up my NetBSD printer
to be visible to MS-WINDOWS and tried to print.
Printing was fine, but the last page produced a PCL XL error,
"Subsystem: KERNEL", "Error: IllegalTag", "Operator 0x25".
(*All* of the real pages printed correctly. The error page
was a separate page.)
What this means is that GhostScript was letting some kind of
garbage out to the printer, while the printer was expecting
PCL. (My printer natively does PCL. I use GhostScript on
NetBSD to make the printer look like a PostScript printer.)
After fiddling around a bit, and peeking at a print-to-file
copy of the data, I discovered that the problem seems to be
lines of the form:
(%%[ Page N ]%%) =
(%%[ LastPage ]%%) =
...these appear to have the intended function of causing a
physical printer to display a message on its local control
panel. However, GhostScript dumps these messages to stdout.
Regretably, stdout is also where (-sOutputFile=-) the PCL
graphical output is going. This appears to be the culprit
in causing my print jobs to get a trailing error page.
GhostScript has a feature that is supposed to protect against
output messages on stdout interfering with using - as the output
file. "-q" is supposed to suppress messages, but it does not
affect *these* messages. I consider this a bug (or else, it's
a bug that there's no option---that I know of---for suppressing
these messages in addition to whatever else "-q" might affect).
I am frankly a bit surprised that this doesn't cause problems
in the middle of printing a multiple-page document, but
perhaps GhostScript saves the errors up to the end?
cd ...pkgsrc/print/ghostscript-gnu && make
(%%[ foo ]%%) =
(note the GhostScript response)
Dunno. I haven't looked at the code yet. Probably a
trivial patch to a bit of code somewhere. I don't
know if the authors of GhostScript consider this a bug
One workaround in my case is to rewire my pipeline to use
-sOutputFile=|lpr instead of outputting to -. (I am run-
ning GhostScript in a printer filter.)
Another workaround should be to do this:
grep -v '^\(%%\[ .*Page.* \]%%\).*=$'
...as a preprocessor to GhostScript. This is a bit of a
hack, but should work and should keep my lpd pipelines
from being further abused by quirks.