Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!mit-eddie!uw-beaver!cornell!batcomputer!prove
From: prove@batcomputer.tn.cornell.edu (Roger Ove)
Newsgroups: comp.windows.news
Subject: Re: NeWS applications should not depend on file access on the server
Summary: checking for files
Message-ID: <8087@batcomputer.tn.cornell.edu>
Date: 2 Jun 89 19:00:10 GMT
References: <7506@hoptoad.uucp>
Organization: Theory Center, Cornell U., Ithaca NY
Lines: 31

In article <7506@hoptoad.uucp>, gnu@hoptoad.uucp (John Gilmore) writes:
> I have seen a number of applications, from Sun's supplied psterm and
> scrolldemo, to GoodNeWS, which load in files on the machine running
> the NeWS server, regardless of where the client program was run from.
> 
> This causes a variety of problems.  The most obvious is that such a
> program doesn't work unless it is installed on both the server and the client.
> If you go to someone else's NeWS screen and run the client, it dies.
> If you try to demo it to a colleague while visiting some other University,
> it dies.  If you reinstall the NeWS server directories, it dies.  Etc.

The only problem with this is that in slow bandwidth situations it
can take a long time to download the postscript.  It should be 
possible to get around this by downloading a small bit of ps
first to check on the file's existence, and on failure download
the rest of the ps.  I tried to implement this and failed,
seemingly due to a NeWS bug.  Putting the file load in a
    {...open file ...} stopped
clause ought to do the trick, but it bombs out anyway when it
can't find the file.  I guess I'm not the only one that has
run into this problem, since the routine /fileexists in the
default init.ps is commented out.  Has anyone found a way to
make this work?
   Anyway, if this worked then users interested in faster 
response could obtain the resident front end, and you could 
still demo the application (with excuses) without it.
   I agree that counting on the existence of files should be
discouraged, and seems contrary to the spirit of NeWS.

Roger Ove
ove@ncsa.uiuc.edu