Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!apple!well!rsmith
From: rsmith@well.sf.ca.us (Ross Smith)
Newsgroups: comp.lang.postscript
Subject: Re: Using readstring with the image operator
Summary: Oops! My first posting got glitched! Please read this instead!
Keywords: readstring, image
Message-ID: <16667@well.sf.ca.us>
Date: 13 Mar 90 10:08:27 GMT
References: <16660@well.sf.ca.us>
Distribution: comp
Lines: 37

To save time and space, I'm trying to transmit binary data to a
PostScript interpreter using readstring instead of readhexstring
in conjunction with the image operator.

Problems start if the binary data contains a ^C (control-C), ^D,
^J, or ^T.  The interpreter apparently ignores (throws away) a
^C, ^J and ^T, and sees a ^D as an end-of-job indicator, thereby
stopping the current job.

On page 12 of Adobe's "PostScript Language Color Extensions" is an
example of using readstring with the image operator.  Unfortunately,
the example is for an interpreter that has a file system.

I know there is a solution as a PostScript printer in HP LaserJet
emulation mode can ignore control-d's at certain times
(when you download a font for example).

Here's an example of what I want to do:

/str 5 string def
72 72 translate
72 72 scale
5 5 8
[5 0 0 5 0 0]
{currentfile str readstring pop} bind
image
^@^A^B^C^D^E^F^G^H^I^J^K^L^M^N^O^P^R^S^T^U^V^W^X % (25 bytes of binary data)
showpage

Does anybody have any ideas on how to get around this problem?  Any help
would be appreciated.

Please forgive my previous posting as this is the first time I have posted
news.  It won't happen again.  Promise!

-- 
Ross Smith  rsmith@well.sf.ca.us   {apple,pacbell,hplabs,ucbvax}!well!rsmith