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.
dhir...@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.
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 ) pcki...@tamu.edu
dhir...@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.
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 jgre...@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.
In article <C0vy89....@rice.edu> rid...@is.rice.edu (Prentiss Riddle) writes: > dhir...@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.
> 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 > jgre...@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.
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
In article <1j5ljrINN...@tamsun.tamu.edu> pcki...@tamsun.tamu.edu (Philip Kizer) writes: >dhir...@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
-- -------------------------------------------------------------- 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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