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From: pwebb@yoyodyne.ncsa.uiuc.edu (Peter Webb)
Newsgroups: comp.lang.postscript
Subject: Writing an Error Handler
Message-ID: <1991May20.210035.12141@ux1.cso.uiuc.edu>
Date: 20 May 91 21:00:35 GMT
Sender: usenet@ux1.cso.uiuc.edu (News)
Organization: National Center for Supercomputing Applications at Urbana Illinois
Lines: 32

I'm trying to write an error handler, since our printer doesn't do anything
useful (i.e. it just doesn't print the page) when an error occurs.  According
to my interpretation of the red book, page 53-54, there is a special dictionary
called $error that contains information about the most recent error.  But when
I run the file below in xps, I get 'undefined in operator load'.  And it won't
print either.  So I'm wondering how to access this dictionary $error, or
alternatively, how to find the name of the most recent error and the operator
that generated it.  Thanks for any help/advice that you can give.

				Peter Webb (pwebb@ncsa.uiuc.edu).

% Install a useful error handler, one that shows a error message in the 
% center of the page.

/printerrdict 5 dict def

/printerr
{ printerrdict begin
  /str 80 string def
  /err /$error load def

  4.25 inch 6.5 inch translate
  err newerror false put
  -120 20 moveto (Error Name:) show
  -100 0 moveto err /errorname get str cvs show
  -120 -20 moveto (Command Name:) show
  -100 -40 moveto err /command get str cvs show
  stop
  end
} def

errordict /handleerror printerr put