Xref: utzoo comp.lang.postscript:2539 comp.text:4480
Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!bionet!csd4.milw.wisc.edu!mailrus!ames!elan!jlo
From: jlo@elan.elan.com (Jeff Lo)
Newsgroups: comp.lang.postscript,comp.text
Subject: Re: Help with eroff and postscript
Message-ID: <593@elan.elan.com>
Date: 26 Jul 89 19:02:04 GMT
References: <374@gizzmo.UUCP> <1893@infmx.UUCP> <1032@esatst.yc.estec.nl>
Reply-To: jlo@elan.com (Jeff Lo)
Followup-To: comp.lang.postscript
Organization: Elan Computer Group, Inc., Mountain View, CA
Lines: 38

In article <1032@esatst.yc.estec.nl> arne@esatst.UUCP (Arne Lundberg) writes:
>In article <1893@infmx.UUCP> cortesi@infmx.UUCP (David Cortesi) writes:
>>Chapter 2 of the eroff manual a while I called Elan tech support and was
>>given this undocumented gimmick:
>>
>>      \!!prologcode@pathname...
>>
>>By the way, since this IS undocumented, don't blame me if they drop
>>it next release - but for now it works pretty well.
>
>They have not dropped it, they changed the syntax to
>
>	\X'prologcode@pathname'
>
>and DOCUMENTED it. This is based on EROFF Release 2.2 for Unix.

As it turns out, the \!!prologcode ... should be used, rather than
\X'prologcode ...' for PostScript, because by the time troff outputs
the pass-through to the driver with \X it has already started emitting
positioning commands.  When the PostScript driver sees any positioning
or text commands it closes out the prolog and starts working within a
save/restore context for the first page, and any additions to the
prolog are disallowed.  The \!! pass-through is totally transparent,
and no formatting commands are output before it *if* the \!! commands
are at the beginning of the source file.  This way the driver will
see the prologcode command before it has closed out the prolog and
the PostScript code will be added to the prolog.  Unfortunately, the
Eroff release 2.2 manuals had been printed before all of the code had
been finalized, and for this reason we are leaving the (currently
undocumented) \!! command in Eroff, and it will be re-documented in
later revisions of the manual.  The \!!prologcode usage has been
documented in the Eroff 2.2 READ.ME file for the last year or so.
Further questions should be directed to the Elan support staff or
to me (support@elan.com or jlo@elan.com).  Thanks.
-- 
Jeff Lo, Elan Computer Group, Inc.
jlo@elan.com, ..!{ames,uunet}!elan!jlo
888 Villa Street, Third Floor, Mountain View, CA 94041, 415-964-2200