Possible solution to determine if default network has changed (MacOS only for now)

[Bob Sneidar]

> On Oct 22, 2019, at 11:05 , Bob Sneidar via use-livecode <use-livecode at lists.runrev.com> wrote:
> 
> Hi all. 
> 
> MacOS only for now. 
> 
> I think I put together a way to tell if the default network has changed since the last time an internet connection took place. It's no good of course, just getting the IP address, as given an identical subnet, you have a 1 in 254 change of getting the same IP address on a different network. We want to be absolutely certain. 

<snip>

Well of course, as soon as I posted I realized 2 adapters on the same network like ethernet and wireless would produce the same results, so here's an iteration that gets the MAC address of the default adapter AND the Router's MAC address. 

Bob S

on mouseUp
   put "route get default" into tShellCommand
   put shell(tShellCommand) into tDefaultAdapter
   put lineOffset("Interface: ", tDefaultAdapter) into tInterfaceLine
   
   if tInterfaceLine = 0 then 
      answer info "No default interface found!" as sheet
      exit mouseUp
   end if
   
   put word 2 of line tInterfaceLine of tDefaultAdapter into tDefaultInterface
   put "ipconfig getpacket " & tDefaultInterface into tShellCommand
   put shell(tShellCommand) into tInterfaceDetail
   put lineOffset("chaddr", tInterfaceDetail) into tInterfaceMACLine
   put word 3 of line tInterfaceMACLine of tInterfaceDetail into tDefaultMACAddress
   put lineOffset("router (ip_mult): ", tInterfaceDetail) into tRouterLine
   put word 3 of line tRouterLine of tInterfaceDetail into tRouterAddress
   put char 2 to -2 of tRouterAddress into tRouterAddress
   put "arp " & tRouterAddress into tShellCommand
   put shell(tShellCommand) into tArpReply
   put word 4 of tArpReply into tDefaultRouterAddress
   put tDefaultMACAddress & cr & tDefaultRouterAddress into tLastMACs
   put tLastMACs
end mouseUp