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Message-ID: <322FE6B3.7085@informatik.uni-hamburg.de>
Date: Fri, 06 Sep 1996 10:54:11 +0200
From: Carsten Benecke <benecke@informatik.uni-hamburg.de>
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Subject: Section 7.6.1.5 Output Filters
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Hi,

you have done a great job. After reading your notes about the BSD
printing
system I was able to write my own input and output filters for our 
postscript printers.

There ist one thing you may want to update in section 7.6.1.5 (Output 
Filters). If you ask lpr for copies (e.g. lpr -#3 text.ps) the lpd will
send the code \031\001 to the of-filter each time it starts the
if-filter.
After an if-filter process has printed one copy the lpd will issue a
SIGCONT (for its of-child). So the of-filter has to receive the code
\031
\001 and stop itself until it receives an EOF on STDIN (e.g. the lpd 
closes the pipe).

This is true for our SunOS (BSD-like) printing system. It may be true
for
FreeBSD.

Bye,
CB
 
-- 
Carsten Benecke 					   
Universitaet Hamburg, FB-Informatik (Rechenzentrum)  
Vogt-Koelln-Str. 30, 22527 Hamburg                   Behoerde:    
9003-2294
email: benecke@informatik.uni-hamburg.de                 Tel.: 040
5494-2294