Warren said:
As to hand-editing a PostScript file, it may not be practical for many
users. Most PostScript files are machine-generated code that is
difficult to read in the first place.
That's certainly true - but when the file is well behaved (which not
all, but many, are), adding 0.80 0.80 scale at the front of the file
will reduce what follows to 80%, whether it is difficult to read or
not. If there is an %%EndSetup comment, putting the scale operator
there is likely to do the trick, if putting it at the top didn't.
After the application's
PostScript prolog renames all the commands, making changes can become
downright challenging.
Application prologs often define short aliases for common operators to
save space in the file, but rarely (I've never heard of it) undefine
the original operators. The application may be using S instead of
scale, but scale will still work.
Because PS is a full programming language, you sometimes run into files
that do something you didn't expect when you change something at the
top. Reader seems in some cases to build in a procedure that
auto-scales and centers every page image to the clipping path's
bounding rectangle, which will make the file seem to ignore any
translate or scale operator you've added. (Simplest way around that is
to set the clip rectangle you want, and let the page scale and center
itself to that.) As with any full programming language, there is no
simple edit guaranteed to do what you want in every case. The upside
is that a simple edit quite often /will/ work on the first try and do
exactly what you want, without any questions about what is happening to
the image representation and quality if you go through format
conversions just to load the file into some WYSIWYG program to make the
change there.
In the cases when you do run into a PS file that seems too 'clever' to
respond to your edits as you expect, you can use something like ps2ps
to interpret it and generate a less clever (and usually longer) PS file
that will behave.
-Chap