Path: utzoo!attcan!uunet!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!sunybcs!bush
From: bush@acsu.Buffalo.EDU (christophe e bush)
Newsgroups: comp.os.os9
Subject: Re: Windows for UNIX... on a CoCo!
Message-ID: <21554@eerie.acsu.Buffalo.EDU>
Date: 11 Apr 90 15:22:53 GMT
References: <1990Apr10.003925.10348@agate.berkeley.edu- <21405@eerie.acsu.Buffalo.EDU> <51416@wlbr.IMSD.CONTEL.COM> <21550@eerie.acsu.Buffalo.EDU>
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In article <21550@eerie.acsu.Buffalo.EDU> marcotte@acsu.Buffalo.EDU (brian r marcotte) writes:
>In article <51416@wlbr.IMSD.CONTEL.COM> pete@wlbr.imsd.contel.com.UUCP (Pete Lyall) writes:
>
>>-Think thats funny? Try setting your DISPLAY environment variable to
>>-someone elses X-Terminal or SUN and running an X application.
>>-
>>-					- Brian Marcotte
>>
>>Not fully accurate. In order to access the remote server, that
>>server's owner must have granted you access, via 'xhost +', or similar
>>mechanism. It's not all out in the open, as implied.....
>>
>>Pete
>
>Well, it must work differently at other places, but here (SUNY
>Buffalo) I know that all you have to do is set the DISPLAY to another
>X-Terminal or SUN, and your applications will appear over their.
>Example: If someone wanted to be funny, they could change your
>background to something rather offensive.
>
>					- Brian Marcotte
>
No, it doesn't work differently here.  The thing is that if you set your 
environment variable to an X-Terminal or Sun Workstation and then run an 
X client from one of the time-sharing machines (i.e. autarch or lictor, sorry
non UB netters, those names won't mean much), most users of X around the 
University have granted those hosts the right to display on their machines.
Since the NCD terminals aren't self contained computers, they must allow 
access to the time-sharing hosts because these hosts serve these terminals.
Therefore, if you are on an X terminal (or any terminal from which 
you can log into one of the time-sharing hosts), you can set your environment
variable to one of the X terminals and run a client to display on that screen.
This includes from a Sun to one of those.  However, if you are on a Sun, you 
may elect to only allow clients running locally on your workstation to display
on your workstation.  Most users again however have allowed access to their 
displays from the time-sharing hosts because clients run on those hosts are 
typically faster. If such a person were logged into a Sun, say Twain in the 
Graphics lab, and only allowed access from twain`s cpu (via 'xhost twain',
 and you did the following from your terminal:
          >setenv DISPLAY twain.cc.buffalo.edu:0.0
          >xloadimage -quiet -onroot some_image

you would get an error message that said you could not open that display.
Some users initialize X on startup and have a command like 'xhost ...' with
a list of allowed hosts after the xhost command.  Alternatively, they may
have simply used 'xhost +' which allows access to their display from all 
known hosts (not necessarily a good thing).  Anyway, this obviously doesn't 
belong in an os9 group, but just wanted to clear things up.  Besides, it may
help someone in emulating an X type windowing environment on their ST or other
os9'er.

                                        - Chris Bush (UCS Graphics Consultant)