Detecting if Mac is connected to network...

Scripting Forums AppleScript | Mac OS X
#1

Hi,

I’d like to know if there’s a way via shell or otherwise to detect whether or not the Mac is connecter to the network.

I have a script that runs at everyone’s login. It mounts a server, and copies files down to the local hard drive. However, if the script runs on a laptop that’s not connected to our network, I’d like the script to just launch, see that there’s no network, and quit. I though this would work:

try
mount volume "afp://TheServer"
--do stuff
end try --If there's an error mounting the server, don't fret, just quit

But that still generates an error that the user has to say OK to if there’s no network connection at all.

OSX 10.3.9

Thanks,
Carl.

#2

hi carl,

how about:


try
	ignoring application responses
		mount volume "afp://TheServer"
		--do stuff
	end ignoring
end try --If there's an error mounting the server, don't fret, just quit
#3

Seconding the try-error block methodology here. The problem is that you can detect if your network interface is up or down (via ifconfig), and you can see if you have valid DNS information . . . but does this mean you can get to the server you need? Not always. Best to put it in a try-error block that does nothing interactive on error and lets the script continue running.

“Fail gracefully,” as they might say.

#4

Here’s the error message.

waltr, I tried ‘ignoring application responses’ without luck.

Mikey-San, the try-error block methodology doesn’t work. It avoids an AppleScript error, but the error message above still pops up. (twice, actually). I’ll look into ifconfig.

I ended up ping’ing our local intranet site for a response before trying to mount the server.

Thanks for the input,
Carl.

#5

Ok, I got some help with ifconfig, and I think that’s the more elegant solution.

#6

Er, yeah. That’s what I get for posting when I’m high on crack. I should’ve realized that you were talking about the Finder’s “server not found error”, not an AppleScript error.

Yeah, you will likely have to dig into ifconfig and perhaps even ping.

#7

hi carl,

sorry the solution didn’t work. the error must be coming from another part of your code, because when i run your example here with the ‘ignoring’, it fails silently. possibly from the ‘–do stuff’ portion.

let us know what you come up with.

#8

I have the same problem (machines that may or may not be connected). Here’s an excerpt from a script I’ve been using for some time:

set serverURL to "[url=http://www.google.com]www.google.com[/url]" -- use the URL (or an IP address) of your server, or one that you know is ALWAYS up
set netStatus to "offline"
set shellCmd to "ping -q -c 1 " & serverURL & " | grep \"packet loss\"  | awk '{ print $7 }'"
set ifInfo to do shell script shellCmd
if ifInfo = "" or ifInfo = "100%" then
	beep
	set msg to "Either you don't have an active network connection, or the file server is not available."
	display dialog msg buttons {"OK"} default button 1 with icon note
else
	set netStatus to "online"
end if

The shell command will return an empty string if it can’t locate the URL, or “100%” if the machine is not responding (i.e., it gets a 100% packet loss). If everything is working OK, you get some percentage less than 100% (usually zero).

I hope you find this useful.

#9

hi carl,

one more try:


try
	ignoring application responses
		mount volume "afp://TheServer"
	end ignoring
end try --If there's an error mounting the server, don't fret, just quit


set chkDisk to list disks

if "TheServer" is in chkDisk then
	display dialog "works"
	--do stuff  **Moved do stuff to here**
else
	quit
end if