From: Marco Atzeri <marco.atzeri@gmail.com>
To: cygwin@cygwin.com
Subject: Re: ctrl-c doesn't reliably kill ping
Date: Wed, 16 Mar 2016 13:25:00 -0000 [thread overview]
Message-ID: <56E95EA2.8070800@gmail.com> (raw)
In-Reply-To: <56E75B3E.7020102@farance.com>
On 15/03/2016 01:45, Frank Farance wrote:
> I have been having this problem with "ping". If I "ping" a location
> that doesn't exist, then "ping" just hangs and cannot be killed via
> "kill -KILL [pid]".
>
>
> Back to the problem, so when I type
>
> $ ping some.unknown.host
>
I do not succeed to replicate.
CTRL-C works fine for me
$ type ping
ping is hashed (/usr/bin/ping)
$ ping 172.21.1.254
PING 172.21.1.254 (172.21.1.254): 56 data bytes
----172.21.1.254 PING Statistics----
4 packets transmitted, 0 packets received, 100.0% packet loss
or I have not a biased DNS answer.
> according to "ping", the hostname resolves to 90.242.140.21 (as per the
> explanation above), but I cannot kill "ping". I tried "ping" with a
> limited packet size and count so, in theory, "ping" would die on its own
> after 10 packets, such as:
>
> $ ping some.unknown.host 50 10
>
> but it still hangs rather than timing out. If I ping to some actual IP
> address that is unresponsive (route-able to the last subnet, but dies on
> the floor at the end), then I can kill via ctrl-c. My only solution to
> the hanging "ping" is to kill the terminal window.
>
> Any suggestions on:
>
> - Why "ping" behaves this way?
> - How to avoid this problem?
>
> Thanks, in advance.
cygwin ping is based on very old source from a time where people was not
cheating on protocol answer.
http://ftp.arl.mil/mike/ping.html
(the author passed away 16 years ago..)
can you send me a strace to see where the program is stacking ?
No promise to find a solution but I will look on it.
Regards
Marco
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next prev parent reply other threads:[~2016-03-16 13:25 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-14 17:18 ctrl-c doesn't reliably kill applications Björn Stabel
2016-03-14 23:39 ` Kaz Kylheku
2016-03-15 0:46 ` ctrl-c doesn't reliably kill ping Frank Farance
2016-03-15 11:05 ` Andrey Repin
2016-03-15 11:43 ` Adam Dinwoodie
2016-03-16 14:46 ` cyg Simple
2016-03-16 4:56 ` Kaz Kylheku
2016-03-16 11:50 ` Andrey Repin
2016-03-16 14:51 ` cyg Simple
2016-03-16 15:57 ` Michael Enright
2016-03-16 17:33 ` Kaz Kylheku
2016-03-16 18:10 ` Lee
2016-03-17 21:10 ` Frank Farance
2016-03-17 21:29 ` Marco Atzeri
2016-03-15 15:13 ` Warren Young
2016-03-16 13:25 ` Marco Atzeri [this message]
2016-03-17 20:04 ` ctrl-c doesn't reliably kill applications Björn Stabel
2016-04-18 21:38 ` Aaron Digulla
2016-04-19 9:13 ` Corinna Vinschen
2016-04-19 16:30 ` Aaron Digulla
2016-03-16 16:07 ` ctrl-c doesn't reliably kill ping Lee
2016-03-16 16:50 ` Warren Young
2016-03-16 17:52 ` Lee
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