🚀 go-pugleaf

carl@SOL1.GPS.CALTECH.EDU (Carl J Lydick) writes: : In article
<3669@ecicrl.ocunix.on.ca>, clewis@ferret.ocunix.on.ca (Chris Lewis) writes: :
>In article <1992Aug2.001052.23580@cco.caltech.edu> carl@SOL1.GPS.CALTECH.EDU
>writes:
: >|In article <3668@ecicrl.ocunix.on.ca>, clewis@ferret.ocunix.on.ca
: >|(Chris Lewis) writes:
: >|>Almost all applications use this convention.  Though, there are some
: >|>stupid broken ones.  Ie: WP apparently leads files with <control-D>%!.
: >
: >|Which is, in my opinion, a reasonable thing to do, as it's the only way to
: >|guarantee that the previous PostScript program has ended before yours
: >|starts.

Sorry to jump into the middle of a thread, but starting a file with
<control-D>%! is NOT a reasonable thing to do.  The purpose of the %! at the
beginning of the file is to create a signature in the first 16 bits that
identifies the file as a PostScript fille.  If the file starts with
<control-D>%!, the first 16 bits are based on <control-D>%, not %!, and the
signature is therefore not one of a PostScript file, conforming or otherwise
(see pg 265 of edition 1 of the Red Book).  A print spooler intelligent enough
to interpret and act on this signature would not pass the file to the printer
as PostScript source, but would interpret it differently, perhaps printing it
as a text file.  PC-type printer drivers may not use the signature and make the
distinction, but more sophisticated drivers will.

Now, on to the question at hand...

Pg 174 of the Green Book (PostScript Language Program Design, by Adobe Systems,
Inc):

The batch job model under which PostScript printers normally operate is founded
on individual print files.  That is, a single job is defined from the initial
byte through the final end-of-file indication.  The end-of-file (EOF) should
*never* be contained in the document file itself; it is part of the
communication dynamics.  In fact, the EOF marker for, say, a serial port is
much different than the EOF indication on a packet network.

Any typos are my fault.  Hope this helps.

                                         Gary
-- 
Gary J. Henderson
gary@iscnvx.lmsc.lockheed.com
#include <std/disclaimer.h>