Path: utzoo!attcan!uunet!motcid!murphyn
From: murphyn@cell.mot.COM (Neal P. Murphy)
Newsgroups: comp.lang.postscript
Subject: Re: EPS
Keywords: EPS
Message-ID: <604@cherry5.UUCP>
Date: 20 Dec 89 16:25:36 GMT
References: <1989Dec18.131827.11383@swssai.uucp> <1989Dec19.174416.2279@usenet.ins.cwru.edu>
Organization: Motorola Inc. - Cellular Infrastructure Div., Arlington Heights, IL 60004
Lines: 56

In article <1989Dec19.174416.2279@usenet.ins.cwru.edu> dkazdan@cwsys2.UUCP (David Kazdan) writes:
>In article <1989Dec18.131827.11383@swssai.uucp> alain%swssai.uucp@uunet.uu.net (alain hsiung) writes:
>>
>>
>>Does anyone knows of the existence of a program/filter that transform
>>a plain Postscript file into an EPS (Encapsulated Postscript) file?
>
>
>What exactly *is* the difference?  My programs that generate this sort of stuff
>all produce .eps files and I have wondered what "regular" PS files are.
>
>--David

he difference:

regular PostScript code:
---------------------------------------------------------------------------
72 360 moveto
/Helvetica findfont 72 scalefont setfont
(Postscript) dup stringwidth pop 468 add 2 div 0 rmoveto show
showpage
---------------------------------------------------------------------------

eps PostScript code:
---------------------------------------------------------------------------
%!PS-Adobe-1.0
%%Title: PostScript
%%Creator: Neal P. Murphy
%%CreationDate: 20 December 1989 (DEC-20 day, for you fans who are still out there)
%%DocumentFonts: Helvetica
%%Pages: 1
%%BoundingBox: 72 350 540 450
%%EndComments

%%Page: 1 1
%%PageFonts: Helvetica

72 360 moveto
/Helvetica findfont 72 scalefont setfont
(PostScript) dup stringwidth pop 468 add 2 div 0 rmoveto show
showpage

%%Trailer
---------------------------------------------------------------------------

You'll note thtat the executable code is identical in each case. The difference
is found in the comments; the comments enable some other application to figure
out the sizes and requirements of a PostScript object, allowing it to include
the object in its own file and perhaps even manipulate it. An example is a
print queue mangler, which will read these comments to find out what fonts
need to be downloaded to the printer, to print the pages in reverse order,
perhaps even to change its layout - 1-up to 2-up, for example. While both are
perfectly valid PostScript code, the latter has structured comments which allow
other applications to use the code within.

NPN