I need to help out my grandmother with her mac occasionally. Now it’s much easier if I can just VNC straight into her machine. Unfortunately, it’s behind a router. But that’s OK. As usual, ssh tunnels to the rescue.
Unfortunately, she’s not really capable of using the command line. So it’s out with the AppleScript!
I wanted a little icon she could click to set up an ssh tunnel. That tunnel should then be torn down when the app closes. This is what I ended up with.
global pid
on run
set sshCmd to "ssh -i ~/.ssh/vnc happygiraffe.net -R 5900:localhost:5900 -N"
set pid to (do shell script sshCmd & "</dev/null >/dev/null 2>&1 & echo $!")
display dialog "Connected to happygiraffe.net"
end run
on quit
do shell script "kill " & pid
continue quit
end quit
There’s a few interesting points about this.
- You have to redirect stdin/stdout/stderr to
/dev/nullordo shell scriptwill never return. - I didn’t realise, but you capture the output of
do shell scriptby enclosing it in parentheses. Yes, this is basic AppleScript. but it’s all new to me. - The
on runandon quithandlers let you doSave As...application bundle. So you end up with a clickable application.on quitmust callcontinue quitor you end up with an immortal app…
- The ssh command itself has a couple of interesting features.
-i ~/.ssh/vncuses a custom key that I set up, instead of having to rely on a password.-R 5900:localhost:5900forwards port 5900 on happygiraffe.net back to port 5900 on her computer.-Nmeans “do nothing” instead of firing up some shell on my server.
At some point, I might extend this so that there’s a Window with a connect / disconnect button. But that will involve AppleScript Studio, which I don’t have on this computer.
So now I should be able to help clear up any, errr, “incidents”. Hopefully.
Jabbering Giraffe 