PostScript support for clients?
dhi...@hamp.hampshire.edu
seems the number of .PS files in Gopherspace is increasing, but they are still
regarded as plain text files by most clients.
dh.
Philip Kizer
On one of the experimental servers here on the TAMU campus, I have marked
the postscript files as type image. I then specify as the viewing program
in the clients, a script that will check the magic number (the first two
bytes of the file in this case) of the file to see if it is a postscript
file (the first two bytes being '%!'). If it is postscript and the DISPLAY
is set, I call 'ghostview' on the file, otherwise I call 'ps2ascii | less'
on the postscript file.
If the file is not postscript, I assume it's a generic image (JFIF [JPEG],
GIF, TIFF, XBM, etc...) and call the normal 'xv -perfect' on the file.
This solution seems to work wonderfully, but it would be nice to have a
cleaner solution.
I've heard of references to gopher+ coming out, but with a fairly rapid
expire set, I haven't seen anything first hand. Could postscript be
added as a type to the 'official' distribution or should we wait for
the new protocol/format? How long before we see more changes? Does
anybody else desire this?
Something else desired here is for the client to fork the viewing program
in the background (as xgopher already does), and wait for the SIGCHLD
before cleaning up the temporary file.
These are fairly innocuous modifications, but (again), in what direction are
things heading, and what should (and are we able to) contribute?
Thank you,
philip
____________________________________________________________ Philip Kizer ___
Texas A&M Unix Workstation Group ( 409 862-4120 ) pck...@tamu.edu
Prentiss Riddle
This is a good question, which gets asked often enough that it should
perhaps be in the FAQ file.
PostScript is a programming language which, in the most common
implementations, includes functions which could be used by the
malicious to create trojan horses. The functions appear to be powerful
enough to delete files, list directories, mail away data from your
system, and conceivably even implement PostScript viruses.
What is needed is for PostScript previewers to be made available on all
the major Gopher platforms which have "safe" modes (that is, which
allow you to turn off these scary functions). When this came up on the
net a few months ago, a couple of people (notably
jgr...@morganucodon.cis.ohio-state.edu) proposed safe mode patches to
GhostScript, the GNU PostScript interpreter. I heard at GopherCon that
a new official release of GhostScript would soon appear including a
safe mode, but I haven't seen it yet. Even if GhostScript (which runs
under Unix and DOS) is taken care of, there are other platforms to
worry about.
Until these problems are solved and PostScript interpreters are
available which have been widely approved as safe, I would be very
cautious about executing PostScript acquired from across the net, and I
would not add PostScript capability to the Gopher clients on my
system.
-- Prentiss Riddle ("aprendiz de todo, maestro de nada") rid...@rice.edu
-- Unix Systems Programmer, Office of Networking and Computing Systems
-- Rice University, POB 1892, Houston, TX 77251 / Mudd 208 / 713-285-5327
-- Opinions expressed are not necessarily those of my employer.
Richard W. Wiggins
Everything Prentiss reports here is accurate. There is another avenue of
hope: Adobe Systems offered hints of a multi-platform Postscript viewer
called Carousel last year, and announced it under the name Acrobat at
the last Comdex. From what I hear we may see this product by mid-year.
Depending on pricing and its built-in safety features, this could be
the answer we're all looking for. It's likely to be important not just
for us Gopher types but for lots of applications.
For everyone building a CWIS in Gopher, Postscript as a lowest common
denominator would be valuable in two ways -- 1) we could deliver documents
with all the rich font changes, proportional text, diagrams, etc; and
2) we could get out of the business of "un-desktop publishing"
handouts and brochures that various units have spent a lot of effort
Quarking or Pagemaking. In many cases the final editing of a document
is done in a desktop publishing tool, and the added effort to get the
original keystrokes back into ASCII delays or precludes getting documents
mounted on Gopher.
/Rich Wiggins, Gopher Coordinator, Michigan State U
Susan Feng
>dhi...@hamp.hampshire.edu writes:
>>Are there any Gopher clients that can display PostScript files on the fly? It
>>seems the number of .PS files in Gopherspace is increasing, but they are still
>>regarded as plain text files by most clients.
>
>On one of the experimental servers here on the TAMU campus, I have marked
>the postscript files as type image. I then specify as the viewing program
>in the clients, a script that will check the magic number (the first two
>bytes of the file in this case) of the file to see if it is a postscript
>file (the first two bytes being '%!'). If it is postscript and the DISPLAY
>is set, I call 'ghostview' on the file, otherwise I call 'ps2ascii | less'
>on the postscript file.
>
Here is another soulution:
We modified gopher client to call "ghostview" if the file is a PostScript
file, otherwise call the default pager command to display it. It seems to
work fine. The released version of gopher clients will still be able to
"read" PS file if the server is kept intact, i.g. the PS file is marked
as type "text".
Thank you,
Susan Feng
--
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Xueshan Feng (Susan Feng) | Tel.: (071) 5895111 x 4975
Computer Centre, Imperial College | E-mail: s.f...@cc.ic.ac.uk
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