Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ukma!tut.cis.ohio-state.edu!att!cbnewsh!wcs
From: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 ho95c.att.com!wcs)
Newsgroups: comp.lang.postscript
Subject: Re: ^D embedded in PS files
Message-ID: <645@cbnewsh.ATT.COM>
Date: 16 May 89 15:12:46 GMT
References: <8905051356.AA01321@decwrl.dec.com>
Reply-To: wcs@cbnewsh.ATT.COM (Bill Stewart 201-949-0705 ho95c.att.com!wcs)
Organization: Your typical phone company involved in your typical daydream
Lines: 28

In article <8905051356.AA01321@decwrl.dec.com> batcheldern@hannah.dec.com (Ned Batchelder, PostScript Eng.) writes:
]In article <7207@pogo.WV.TEK.COM>, richk@pogo.WV.TEK.COM (Richard G.Knowles)
]states that the Unix spooler is "brain-dead" because it cares about ^D.
]
]How should a spooler detect the end of the job?  [...]
]^D's are the provence of the spooler ENTIRELY.  THEY DO NOT BELONG IN FILES.
]THEY ARE NOT PART OF THE POSTSCRIPT LANGUAGE.  PERIOD.  To anyone who

But *why* should a spooler care about the end of a job?  A typical
postscript program sets up some initial stuff, does some pages each ending
in showpage, and does some cleanup.  The main things a spooler does that are
job-based are preloading fonts and reversing pages, which do require support
from the language to do (if you count EPSF as part of the language, and if
not, you shouldn't try reversing pages).

So if the printer gets stuff starting with EPSF introductory comments, it
should do whatever printer-setups it needs, and process stuff until it gets
to an EPSF terminating comment.  If it gets stuff starting with anything
else, it should just keep reading data and doing a page at a time until
something interesting comes along to reset it.  I agree that ^D  is not the
ideal character to put in a file, but it's real ASCII, and should be
tolerated (albeit treated as an undefined word if nobody's used it.)

-- 
# Bill Stewart, AT&T Bell Labs 2G218 Holmdel NJ 201-949-0705 ho95c.att.com!wcs
	# also found at 201-271-4712 tarpon.att.com!wcs 
# But the treaty says we have to give Panama back to the Panamanians!
#    Don't worry - we'll think of something.  Corruption?  Yeah, that's it!