Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!snll-arpagw!paolucci
From: paolucci@snll-arpagw.UUCP (Sam Paolucci)
Newsgroups: comp.lang.postscript
Subject: Re: PS libraries
Message-ID: <100@snll-arpagw.UUCP>
Date: 28 Apr 89 15:25:23 GMT
References: <2994@daisy.UUCP> <775@adobe.UUCP> <8751@polya.Stanford.EDU> <98@snll-arpagw.UUCP> <22489@ccicpg.UUCP>
Reply-To: paolucci@snll-arpagw.UUCP (Sam Paolucci)
Organization: Sandia National Labs, Livermore, CA
Lines: 51

In article <22489@ccicpg.UUCP> evans@ccicpg.UUCP ( Scott Evans) writes:
->In article <98@snll-arpagw.UUCP>, paolucci@snll-arpagw.UUCP (Sam Paolucci) writes:
->> Thus it appears to me that in a PC world where access to the serial
->> device is easy and transparent, the only option is for the application
->> program to append a ^D to the end of the PostScript output.  This
->> guarantees that the file will be handled properly whether it is
->> redirected to the serial device, or later copied to it.
->> 
->> 
->Can we help it if the PC is a "brain-dead" kind of machine and has no
->other way telling when it gets to an "end of file"????
->
->This is purely a kludge to get around a limitation on the PC.  It is
->especially apparent when you see a ^D not only at the end of a Postscript
->file but also at the beginning!!!
->
->The postscript printer that is hooked up to our Unix system does not like the
->^D at the beginning of the file and so we have to filter all the files that
->come from a PC before they can be printed.  

This is baloney, and I'll tell you why.  First of all I was not talking
about what you refer to a "brain-dead" PC.  I was talking about an Amiga.
Remember, the whole world does not revolve around big blue.  But that is
besides the point.  A copy command (or cat, or type, or ...) should not
append anything to a file.  It is not their job.  These commands have
no way, and should not have any way of telling that you are redirecting
their output to your serial device.  Only the user knows this.  The
standard joe user does not know that Adobe defines a "job" as a file
which includes a ^D at the end.  Furthermore, to my knowledge, nowhere
in the PostScript red book does it say explicitly that a "job" consists
of a PostScript program terminated by a ^D.

Granted, anytime you include binary data in a file reduces portability.
But I was referring to a DEDICATED PostScript printer attached to the
serial port of a machine that might not have a print spooler, and where
the serial port can be directly and easily accessible to the user with
a simple copy command.  In this case it is a lot more convenient and
efficient to have a utility that strips off ^D at the end of a file
occasionally when you have to move it over some other system, than to
have to append a ^D every time you print something.

Finally, I never excused the sending of a PostScript file with ^D's
to a networked printer spooler.  That is just bad manners.  But that
is a different question.


-- 
					-+= SAM =+-
"the best things in life are free"

				ARPA: paolucci@snll-arpagw.llnl.gov