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10.4: Use multiple simulataneous GUI accounts System 10.4
Tiger only hintHere's how to have two GUI users active at one time on the same machine. This hint is a summary of this hint on the macosx.com forums; read the original post for much more detail.

Here are the basic requirements: After you have two or more accounts set up on one Mac, install OSXvnc and start the server. Once started, Fast User Switch to the other user on the machine.

Now from another computer, use a VNC viewer like Chicken of the VNC and point it to the Mac. Even though the Mac is logged in as another user, your VNC session goes to the original account, allowing both of you to use the machine at the same time.

When testing, this is seemed to work well, although you have to wonder if there will be problems with system calls from the same programs happening simutaneously. I've only been running this for about two hours, but no problems so far.
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10.4: Use multiple simulataneous GUI accounts | 14 comments | Create New Account
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10.4: Use multiple simulataneous GUI accounts
Authored by: skrawcke on Aug 15, '05 11:41:16AM
osx 10.4 comes with a VNC server built in.. go to the System Preferences -> Sharing -> Apple Remote Desktop. then click on Access Privileges and you will see a chkbox called
VNC viewers may control screen with password:

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10.4: Use multiple simulataneous GUI accounts
Authored by: ihint on Aug 15, '05 12:07:55PM

This hint will not work with the built-in vnc server. You need to use OSXVNC.

If you use the built-in vnc server, your vnc session will always be the active user session.



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10.4: Use multiple simulataneous GUI accounts
Authored by: Cameroon on Aug 15, '05 12:43:08PM

Furthermore, the built-in VNC server is kind of poor, both in range of client options it will accept and speed.

Go with OSX VNC Server, definitely.



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10.4: Use multiple simulataneous GUI accounts
Authored by: ssargon on Aug 15, '05 12:15:52PM

"When testing, this is seemed to work well, although you have to wonder if there will be problems with system calls from the same programs happening simutaneously. I've only been running this for about two hours, but no problems so far."

Most moderns systems uses special procedures when it comes to noninterruptable system-(mostly)calls so I can understand your consern over this. But i think that the only problem you can run into is that the system will wait until it gets access. It should not take long time (in human terms :-).



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10.4: Use multiple simulataneous GUI accounts
Authored by: Cameroon on Aug 15, '05 12:48:25PM

There are likely other side effects; some programs (iChat I believe is one) can only be active/connected from one account at a time. General use word processing, browsing, etc. would be fine I imagine.



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10.4: Use multiple simulataneous GUI accounts
Authored by: Auricchio on Aug 15, '05 12:24:25PM

Since each instance of a program is a separate process, there should be no problem with system calls. Thus, if both users run, say, Photoshop, each one will be separate.

Of greater importance is whether the program assumes only one user at a time. Photoshop Elements 2, for example, assumes it can store temporary image data in its Application directory! This means that two users doing the same operation will have their data collide. Not good, and it's a just basic programming error.

Some System Preferences might also collide, because they operate across account boundaries.

---
EMOJO: mojo no longer workin'



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How 'bout 2 Users on Same Computer on Same Screen!
Authored by: EatingPie on Aug 15, '05 05:00:56PM

I don't have two accounts, but here's a suggested use...

On the Mac, fire up a VNC client (like Chicken of the VNC), and then point VNC to YOUR OWN IP address. Log into the 2nd account as per instructions in the hint.

Viola, you are now working two users on the same machine on the same screen/kbd at the same time!! :)

-Pie

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-Pie
<http://www.storybytes.com>



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10.4: Use multiple simulataneous GUI accounts
Authored by: taxi on Aug 15, '05 11:06:58PM

The only drawback I can see (besides the fact that VNC isn't as fast as I'd like) is that you need to log in at some stage, and run the Server.

I'd like to be able to have the server run as my user before I log in, or be able to 'log in', in the background so I can remotely work.

On a related note:

Does anyone know if WindowServer applications can now be started on a Switched-Out user's account, from a ssh connection for instance?



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10.4: Use multiple simulataneous GUI accounts
Authored by: danieleran on Aug 15, '05 11:38:03PM

When you log in via an ssh shell, you can't start graphic applications the way you can from terminal.app.

The ssh environment, and other things happening under the level of the login manager (such as daemons in the background) can't directly interact with things in the graphic application world.



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10.4: Use multiple simulataneous GUI accounts
Authored by: themacnut on Aug 16, '05 01:58:29AM

Actually you can start graphic apps from ssh. BUT you have to be logged in via the GUI as the same user. If you're not, you get WindowServer errors.

What you'd have to do if you're logged out at the GUI is directly start the vnc server part of OSXvnc from the command line, THEN log in via the login window. Instructions for command-line starting of the vnc server are at http://www.redstonesoftware.com/osxvnc/OSXvnc.html

Look for the question about starting OSXvnc from the command line.



---
The MacNut
Owner, ClarisWorks/AppleWorks Email List
http://awlist.macnuthome.com



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10.4: Use multiple simulataneous GUI accounts
Authored by: DylanMuir on Aug 16, '05 03:57:45AM

Unfortunately this won't work if someone else is already logged into the machine. In that case OSXvnc complains that only root or the console user can start the server. If you use sudo, you'll just get the current console session; not your own...

This is true even if you're already logged into the machine but FUSed out...

D.



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10.4: Use multiple simulataneous GUI accounts
Authored by: jweida on Sep 21, '05 11:18:35AM

What I do, is run one instance of OSXVnc at startup that will always be tied to the active session. That way, no one has to be logged in. Then I run my own OSXVnc at user login. That way, if I need to connect after a reboot, I just connect to display :0 and login. Then I can login again on display :1 and get my own display.



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Or, use su username -c
Authored by: dom on Aug 16, '05 11:34:30AM
You can run any program as another user using su -c. For example, to run Terminal as bob, do
su bob -c /Applications/Utilities/Terminal.app/Contents/MacOS/Terminal


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READ what the author of OSXvnc says about this
Authored by: Krioni on Sep 21, '05 01:49:19PM
This is a fun hint (although it was described in more detail by the author of OSXvnc over a month ago).

You may want to read some important caveats (especially the one about keyboard modifiers leaking form the physical user to all others):
OSXvnc Multiple Desktop Sessions.

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