Path: utzoo!attcan!uunet!decwrl!bacchus.pa.dec.com!wsl.dec.com!heiney
From: heiney@wsl.dec.com (Bob Heiney)
Newsgroups: comp.lang.postscript
Subject: Re: showpage-layering (eg. print-odd-pages-only)
Keywords: showpage, problems
Message-ID: <1990Aug15.163702.15828@wrl.dec.com>
Date: 15 Aug 90 16:37:02 GMT
References: <30532.26c6bf13@ccavax.camb.com> <1990Aug14.163226.1253@wrl.dec.com>
Sender: news@wrl.dec.com (News)
Reply-To: heiney@wsl.dec.com (Bob Heiney)
Organization: DEC Western Software Lab
Lines: 33

First, sorry to all (including me) who suffered through miswrapped
text on my previous posting.  I didn't realize my window was more
than 80 columns wide.

Anyway, I looked at version 2.1 of the Document Structuring Conventions
from Adobe and found the following relevant quotes:

(Section 4, "Conforming Files", p. 5)

	... If these structuring conventions are to be employed, care
	should be taken to use them correctly and in accordance with
	their intended goals.  Failure to do so may result in
	unexpected behavior of document files within some document
	handling systems.

(p. 6)

	If the showpage operator is used with save and restore, the
	showpage operator shall occur after the page-level restore
	operation.  The motivation for this is to be able to handily
	redefine the showpage operator to have side effects in the
	printer VM such as maintaining page counts for printing n-up
	copies on a single sheet of paper.  If the showpage is executed
	within the confines of a page-level save/restore, then attempts
	to redefine showpage to perform extra operations will not
	work as intended.

Thus, the original poster can see that his software *ought* to work.
If only every file that claimed to be well-behaved actually was.

Bob Heiney
Graphics Consultant
heiney@dec.com