Yes, trying to figure out WHY the connection failed is trickier. I think you
are right that Safari pings an IP (to exclude DNS problems) and then looks at
the response. A ping that has no route will report something like Destination
Unreachable as opposed to timeout. On my Apple terminal, if I ping a bogus DNS
name, I get cannot resolve <hostname>: unknown host. If I ping a bogus IP, I
get a timeout. If I disable all network adapters I get a timeout AND sendto: No
route to host. Windows probably does something similar.
I suppose you could simply ping through a shell and then peruse the responses.
> On Mar 2, 2018, at 10:09 , Graham Samuel via use-livecode
> <firstname.lastname@example.org> wrote:
> Bob of course you’re right - in my particular case, anyway, I just want to
> know if I can access me chosen server or not.
> But one could certainly imagine programs that would want to know if they were
> wasting their time offering their users a broader internet access - I mean
> any program that allows the user to specify addresses (like a browser does)
> would want more of an “is there or isn’t there?” approach. On my Mac, the
> Apple browser Safari can announce “you are not connected to the internet”.
> Maybe it just pings a trusted source and waits for a reasonable time for the
> Anyway what I noticed in my little experiment was that the reaction of the
> script when the internet wasn’t available was very rapid (certainly less than
> half a second), which means that just trying to get the file and then looking
> for an error response would probably be OK for a human user, since there is
> no prolonged wait.
> As you see, I am reluctant to do anything that’s at all complicated!
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