Filtering ^D from PS files

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4 total messages Started by Richard P. Daley Wed, 30 Dec 1992 03:24

#5857

Author: Richard P. Daley
Date: Wed, 30 Dec 1992 03:24

22 lines
1320 bytes

From a Postscript neophyte...

I understand that some PC software is in the habit of creating Postscript files
which contain ^D characters, to make printing via serial connections work.
I have various software packages on my SPARCStation which print, fax, and view
Postscript files, and some of these packages don't like finding ^D characters
imbedded in the Postscript.  I'd like to use a simple filter to get rid of the
^D characters.

Can anyone tell me whether it's safe to strip out all ^D characters from an
arbitrary Postscript file?  Is it possible for a Postscript file to have
^D characters that can't be stripped out?  For example, is there a way to
imbed bitmaps or other binary data using non-printable characters?

Should my filter be a little smarter, and only filter out ^D characters that
show up at the beginning of the file?  Is there any software which is
creating Postscript files with a ^D at the end as well?

Thanks for any advice,

Rick Daley
rdaley@sbi.com

Re: Filtering ^D from PS files

#5863

Author: Manuel Veloso
Date: Wed, 30 Dec 1992 19:38

16 lines
1499 bytes

In article <1602@twinkletoes.sbi.com> Richard P. Daley,
rpd@twinkletoes.sbi.com writes:
>Can anyone tell me whether it's safe to strip out all ^D characters from
an
>arbitrary Postscript file?  Is it possible for a Postscript file to have
>^D characters that can't be stripped out?  For example, is there a way to
>imbed bitmaps or other binary data using non-printable characters?

I tried to do this once because binary images would inevitably have a 
ctrl-d in them. Stripping them out doesn't work, nor does converting 
them. And on the mac, there's no reliable, simple way to tell if the 
ctrl-d is part of a binary image. But if the ctrl-d's are in a certain 
place (before %%BeginDocument or after %%EOF) then they're probably safe 
to strip.

Manuel

Re: Filtering ^D from PS files

#5865

Author: Paul Gilmartin
Date: Thu, 31 Dec 1992 00:15

16 lines
1278 bytes

Richard P. Daley (rpd@twinkletoes.sbi.com) wrote:
: I understand that some PC software is in the habit of creating Postscript files
: which contain ^D characters, to make printing via serial connections work.
: I have various software packages on my SPARCStation which print, fax, and view
: Postscript files, and some of these packages don't like finding ^D characters
: imbedded in the Postscript.  I'd like to use a simple filter to get rid of the
: ^D characters.

It may help to concatenate your PostScript file after the following:

%!
<04> cvn {} def

which redefines the ^D as a no-op to PostScript.  You might also
want to try a similar trick for the ^Z with <1A> instead of <04>.
This should preserve those characters in binary images.

Re: Filtering ^D from PS files

#6563

Author: Rick Clements
Date: Mon, 04 Jan 1993 17:52

19 lines
1324 bytes

In article <1602@twinkletoes.sbi.com> rpd@twinkletoes.sbi.com (Richard P. Daley) writes:
>From a Postscript neophyte...

>Can anyone tell me whether it's safe to strip out all ^D characters from an
>arbitrary Postscript file?  Is it possible for a Postscript file to have
>^D characters that can't be stripped out?  For example, is there a way to
>imbed bitmaps or other binary data using non-printable characters?

You can remove ^D from files which have ASCII and binary data.  If the file has
raw data you can't.  The serial and parallel ports will handle both ASCII and
binary data.  AppleTalk will handle raw data.

The difference between binary and raw data is binary data has special
characters quoted (^D, ^C, ^S ...).  In level II, the ^D won't appear as a ^D 
in the data.  In level I, different printers quoted binary data differently, so
many programs didn't send  binary data because it wasn't consistant.
-- 
Rick Clements (RickCl@pogo.WV.TEK.COM)

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