How to open a connection without PublicWindowServer set?

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2 total messages Started by Bill Nixon Tue, 22 Dec 1992 01:17

#1928

Author: Bill Nixon
Date: Tue, 22 Dec 1992 01:17

41 lines
1904 bytes

I wrote a little application which allows me to pop up an
alert panel on the Workspace from the command line, ala
/usr/lib/NextPrinter/Inform.

This works great as long as I am doing it from a Terminal
Session I started.  But, it does not work if I rlogin into
the machine.  I know about PublicWindowServer and DON'T want
to turn it on for various reasons.

I tried to su to root and do the same thing, but this
doesn't even work.  I mucked around and read in the
loginwindow(8) man page that an application must be
descended from either the Workspace or be a special system
process such as the printer daemon.  And yes, this seems to
hold true.

Now, how can I get around this?  I want to write a one of
the aforementioned special system processes that can write
to the Workspace without Public Window Server being set but
have no idea what the Workspace is looking for...

Why do I want to do this?  Well, I'd like to put up an panel
on a machine when I am about reboot a machine remotely like
this:

rlogin machine
su
displaymsg "Message is going to reboot in 60 seconds"
sleep 60
reboot

Any pointers to help solve this problem would be greatly
appreciated.  Note that I am trying to do this under
NeXTSTEP 3.0.

Thanks!

-- 
bnixon@fnma.com or ...!uunet!fnma.com!bnixon (NeXT Mail Okay)
Bill Nixon, Senior Programmer Analyst, Advanced Technology, 2H-4S
FannieMae, 3900 Wisconsin Ave NW, Washington, DC 22016  (202) 752-5468

Re: How to open a connection without PublicWindowServer set?

#1940

Author: Gary Ritchie
Date: Tue, 22 Dec 1992 22:08

40 lines
2467 bytes

> 
> Now, how can I get around this?  I want to write a one of
> the aforementioned special system processes that can write
> to the Workspace without Public Window Server being set but
> have no idea what the Workspace is looking for...
> 

I have found one way to do this.  It's not particularly elegant, but it  
works, and it allows each user to enable/disable the feature.  I mention  
using Speaker/Listener because I know it works under these circumstances,  
but Distributed Objects would probably be the best way to go.

First, write a Workspace daemon that has a known public Listener.  To do  
this, you will need the publicCheckInAs: method documented in the latest  
NeXTanswers, otherwise you cannot create a public Listener without turning  
on Public Window Server.

Workspace daemons are non NeXTSTEP programs with a .daemon extension that  
are launched by the WS at login time.  You use the LaunchPaths default to  
get this to happen.  The most elegant way is to have the daemon install  
the default the first time it is run.

Anyway, the user logs in, and the daemon is run as a user process.  Now,  
you write a command-line utility that looks for the known Listener port,  
and sends it a predetermined message (ie. displayMessage:(char *)msg.  The  
daemon pops up a panel, and the job is done.

The only problems I can think of are that (1) each user must install the  
daemon and (2) this won't display a panel on the login screen.  Still, I  
think it would be a handy way to broadcast a message to logged-on users.

Hmm. It's the last day before my XMas holiday, I'm bored, and I realize  
that my answer is a bit obscure.  I'll see if I can get this working in  
the next couple of hours and post it on an archive site.  No promises :-)

---

Gary Ritchie
gary@nshade.uah.ualberta.ca
NightShade Software

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