[ltp] OT: how to time a ping command?

[Eben King]

On Mon, 20 Sep 2004, André Wyrwa wrote:

> Hei,
> 
> > from ping.1:
> > 
> >    -w deadline
> >       Specify a timeout, in seconds, before ping exits  regardless  of
> >       how  many  packets have been sent or received. In this case ping
> >       does not stop after count packet are sent, it waits  either  for
> >       deadline  expire  or until count probes are answered or for some
> >       error notification from network.
> 
> Funny, that's exactly what i'm looking for, but my ping.1 doesn't
> include this and neither does my ping.
> Can you post your --version output please? Mine is from GNU inetutils
> 1.4.2 .

Doesn't have that option, but it does have -V:

[eben@pc eben]$ ping -V
ping utility, iputils-ss020124

> > ping -c 1 somehost > ping_output &
> > sleep 1
> > kill %1
> > grep -q 'some_expr' ping_output && ip_up
> 
> Ahh...didn't know about the %1 thing, thx. I'll take that as a fallback
> if i can't get my ping to support the -w option. ;-)

I did something much faster (which I can't recall verbatim).  It would do 
something like

ping -c 1 somehost > /dev/null &
ping_pid=$!
{ sleep 1 ; kill $ping_pid ; } &
sleep_pid=$!
wait $ping_pid
kill -0 $sleep_pid && # internet connection is up
kill $sleep_pid

(At least that's how I THINK I did it.)  Net effect was that you would
only wait for the timeout if the ping wasn't returned.  Normally there
would just be a ping then life would go on.

-- 
-eben    ebQenW1@EtaRmpTabYayU.rIr.OcoPm    home.tampabay.rr.com/hactar

              An idea that is not dangerous is unworthy of
               being called an idea at all.  -Oscar Wilde