Re: What does this PS code mean ?

[jmburns@ipa.net (Jim Burns)]

In article <858776157.2177.0@cisay25.demon.co.uk>, pkw@elgro.co.uk (Phil
Watkinson) wrote:


> Hi.
> 
> Please could someone tell me what's happening in the following 
> postscript code :-
> 
>         % faxmail prologue file.
>         %
>         /EPSbegin{save gsave 20 20 scale 200 dict begin}def
>         /EPSend{end grestore restore}def
> 
> It is part of the HylaFAX v4.0 fax software and is the user customizable
> part of the email-to-fax gateway.
> 
> The gateway inserts the contents of the file above before generating
> the %%EndProlog marker.
> 
> I've learnt from the excellent 'First Guide to Postscript' website that
> the "20 20 scale" part is magnifying up the coordinates - the gateway
> generates a "0.5 dup scale" line later on in the file - so the user can
> tweak the size of the image.
> 
> The Guide also implies that '/EPSbegin' and '/EPSend' are procedures, 
> but I can't see where they are used... and the procedures names cannot
> be 'begin' and 'end' because they are reserved words, aren't they ??
> 
> I would like to place my own header and footer in the resulting fax
> image, can I achieve this though this code ? 
> 
> Any help, or pointers to further info, greatly appreciated.
> 
> Cheers,
> Phil Watkinson,
> pkw@elgro.co.uk

The begin and end terms are reservered, but they are bein used here for
that for which they were reserved, to begin and end a proceedure.  A
dictionary holding a max of 200 elements is created.

jmb