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From: brown@vidiot.UUCP (Vidiot)
Newsgroups: comp.lang.postscript
Subject: Re: How can I tell if a file is "postscript"
Message-ID: <1448@vidiot.UUCP>
Date: 6 Mar 91 03:17:20 GMT
References: <7647@uceng.UC.EDU> <1991Mar4.075212.12828@lth.se> <1894@chinacat.Unicom.COM>
Reply-To: brown@vidiot.UUCP (Vidiot)
Organization: Vidiot's Hangout
Lines: 35

In article <1894@chinacat.Unicom.COM> woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) writes:
<In article <1991Mar4.075212.12828@lth.se>, d89mb@efd.lth.se (Magnus Bodin) writes:
<> 
<> A file to be accepted by a laser-writer must start with  
<> %!
<> 
<> at the first line. 
<> 
<> Just testing that will do. But that depends on what you're gonna use
<
<This is just plain not so.  The % is a comment.  The interpreter will just
<ignore this line.  NONE of my files use the %!.  It is merely a commenting
<structure having to do with EPS. (Encapsulated postscript).  Some SPOOLERS
<like to see it, but the printer its self could give a rats hind end about it.
<EPS has been defined by Adobe, but it has wound up being a real rats nest
<of complexity.  This application can't interpret that applications eps
<file and vise-versa.  In my opion it is highly over-rated and quite
<useless.  But then again I don't use my postscript printer as an output
<device for canned programs much, except for Pagemaker, Microsoft word,
<and Arts & letters, none of the literaly thousands of programs (well over
<300 disks full) that I have support Postscript so EPS really is no
<big deal for me.  I have rarely derived any benifit from it, though I suppose
<that if I were importing  postscript files it might have some.  Actualy
<the only thing that normally affects anything is the bounding box line.

Not quite.  The %! on the first line is required by the LaserWriter printers
and compatibles.  It is NOT part of the definition for EPSF or EPSI.  If that
special comment line is missing, the LaserWriter series printers will change
to Diablo emulation mode and the PostScript program will print out as a source
listing, i.e., the PostScript code will print as normal text and the program
will not run.
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