Checking for an internet connectio

[Phil Davis]

Hi Peter,

I use "ping" to see if a given server is available. There are fewer bad 
things that can happen using this approach than trying to get a URL. The 
following code came from a recent project (slightly modified to protect 
the innocent) - watch line wraps:


on mouseUp
    answer "Connection status =" && app_connectionStatus("google.com")
end mouseUp



function app_connectionStatus pTargetDomain

     -- attempt to ping the ctrainweb.com server
     switch (the platform)
         case "MacOS"
             put shell("ping -c 1 -t 5" && pTargetDomain) into tShellOutput
             put the result into tResult
             break
         case "Win32" -- PD 20100411
             set the hideConsoleWindows to true
             put shell("ping -n 1 -w 5" && pTargetDomain) into tShellOutput
             put the result into tResult
             break
         default -- all other OSes
             answer "This app cannot run on the" && the platform && 
"platform."
             put param(0) & colon && the platform && "platform not 
supported" into tResult
             break
     end switch

     -- check for connection failure
     if tResult <> empty
     then return false -- failed
     else -- connected, but how well?
         set the itemDel to comma
         if the platform = "Win32"
         then
             get tShellOutput
             filter it with "*(0% loss)*"
         else -- Mac
             repeat for each item tFilter in "* 0% packet loss*,* 0.0% 
packet loss*" -- for different OS versons
                 get tShellOutput
                 filter it with tFilter
                 if it <> empty then exit repeat
             end repeat
         end if
         return (it <> empty)
     end if
end app_connectionStatus


HTH
Phil Davis



On 4/28/12 12:12 PM, Peter Haworth wrote:
> Just put together a procedure for checking for software updates from my
> SQLiteAdmin program.  All works great but I'm wondering the best way to
> check if there is an internet connection.  I tried this out by
> disconnecting my computer from my wireless router and I got an"invalid host
> address" message from libURLErrorData as soon as I called
> libURLDownloadToFile.
>
> I can easily check for that of course but it sounds like that message could
> come back in other circumstances so wondering if there's some other way to
> check for an internet connection before attempting a download.
>
> Pete
> lcSQL Software<http://www.lcsql.com>
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-- 
Phil Davis