[gentoo-user] Ctrl+C not working over ssh?

[gentoo-user] Ctrl+C not working over ssh?

[Andy Wilkinson]

I can't say for sure when this started, as I have gone a while without 
accessing my computer remotely much, but perhaps since my last upgrade 
(which may have included openrc), ctrl-c doesn't work over ssh.  I have 
tested this from multiple workstations and even my droid, using 
different terminal emulators, and have got consistent results.

I'm not even sure where to start looking.  Googling didn't find me much 
(at least, not much that's current at all; 5 year-old ubuntu bugs aren't 
very useful), and I'm not sure at all what might be causing this.  Could 
anyone here point me to something that might be causing this?

Thanks,

-Andy

[gentoo-user] Re: Ctrl+C not working over ssh?

[Hartmut Figge]

Andy Wilkinson:

> I can't say for sure when this started, as I have gone a while without 
> accessing my computer remotely much, but perhaps since my last upgrade 
> (which may have included openrc), ctrl-c doesn't work over ssh.  I have 
> tested this from multiple workstations and even my droid, using 
> different terminal emulators, and have got consistent results.

Using icewm, xterm and no desktop i have connected to my machine.

hafi@i5 ~ $ ssh i5
Password:
Last login: Tue May 24 20:23:25 CEST 2011 from i5.lan.triffids.de on pts/7
hafi@i5 ~ $ ping -q localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
^C
--- localhost ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 999ms
rtt min/avg/max/mdev = 0.011/0.012/0.014/0.003 ms

No problem.

Hartmut
-- 
Usenet-ABC-Wiki http://www.usenet-abc.de/wiki/
Von Usern fuer User  :-)

Re: [gentoo-user] Ctrl+C not working over ssh?

[Todd Goodman]

* Andy Wilkinson <drukargin@gmail.com> [110524 12:24]:
> I can't say for sure when this started, as I have gone a while without 
> accessing my computer remotely much, but perhaps since my last upgrade 
> (which may have included openrc), ctrl-c doesn't work over ssh.  I have 
> tested this from multiple workstations and even my droid, using 
> different terminal emulators, and have got consistent results.
> 
> I'm not even sure where to start looking.  Googling didn't find me much 
> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't 
> very useful), and I'm not sure at all what might be causing this.  Could 
> anyone here point me to something that might be causing this?
> 
> Thanks,
> 
> -Andy

I don't have any problems.  What does 'stty -a' show for the intr= bit?

Todd

Re: [gentoo-user] Ctrl+C not working over ssh?

[Andy Wilkinson]

On 05/24/2011 12:38 PM, Todd Goodman wrote:
> * Andy Wilkinson<drukargin@gmail.com>  [110524 12:24]:
>> I can't say for sure when this started, as I have gone a while without
>> accessing my computer remotely much, but perhaps since my last upgrade
>> (which may have included openrc), ctrl-c doesn't work over ssh.  I have
>> tested this from multiple workstations and even my droid, using
>> different terminal emulators, and have got consistent results.
>>
>> I'm not even sure where to start looking.  Googling didn't find me much
>> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't
>> very useful), and I'm not sure at all what might be causing this.  Could
>> anyone here point me to something that might be causing this?
>>
>> Thanks,
>>
>> -Andy
> I don't have any problems.  What does 'stty -a' show for the intr= bit?
>
> Todd
>
$ stty -a
speed 38400 baud; rows 23; columns 80; line = 0;
intr = ^C; ...

Which looks right, but when I try to use Ctrl-C, this happens:

$ ping localhost
PING localhost (127.0.0.1) 56(84) bytes of data.
64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.037 ms
^C64 bytes from localhost (127.0.0.1): icmp_req=2 ttl=64 time=0.032 ms
^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=3 ttl=64 time=0.032 ms
^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=4 ttl=64 
time=0.034 ms
^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=5 ttl=64 
time=0.032 ms
^Z

This does NOT happen locally: from a console or terminal at the machine, 
I can interrupt just fine.  Ctrl-Z does//work over ssh.

Thanks,

-Andy

Re: [gentoo-user] Ctrl+C not working over ssh?

[Paul Hartman]

On Tue, May 24, 2011 at 5:29 PM, Andy Wilkinson <drukargin@gmail.com> wrote:
> On 05/24/2011 12:38 PM, Todd Goodman wrote:
>>
>> * Andy Wilkinson<drukargin@gmail.com>  [110524 12:24]:
>>>
>>> I can't say for sure when this started, as I have gone a while without
>>> accessing my computer remotely much, but perhaps since my last upgrade
>>> (which may have included openrc), ctrl-c doesn't work over ssh.  I have
>>> tested this from multiple workstations and even my droid, using
>>> different terminal emulators, and have got consistent results.
>>>
>>> I'm not even sure where to start looking.  Googling didn't find me much
>>> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't
>>> very useful), and I'm not sure at all what might be causing this.  Could
>>> anyone here point me to something that might be causing this?
>>>
>>> Thanks,
>>>
>>> -Andy
>>
>> I don't have any problems.  What does 'stty -a' show for the intr= bit?
>>
>> Todd
>>
> $ stty -a
> speed 38400 baud; rows 23; columns 80; line = 0;
> intr = ^C; ...
>
> Which looks right, but when I try to use Ctrl-C, this happens:
>
> $ ping localhost
> PING localhost (127.0.0.1) 56(84) bytes of data.
> 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.037 ms
> ^C64 bytes from localhost (127.0.0.1): icmp_req=2 ttl=64 time=0.032 ms
> ^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=3 ttl=64 time=0.032 ms
> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=4 ttl=64
> time=0.034 ms
> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=5 ttl=64
> time=0.032 ms
> ^Z
>
> This does NOT happen locally: from a console or terminal at the machine, I
> can interrupt just fine.  Ctrl-Z does//work over ssh.

That's so strange...

I'm curious, if you open another terminal and issue SIGINT to that
process (using kill), does it work? I think it should be the
equivalent to hitting ctrl-c interactively.

"trap" command can be used in scripts to block certain signals... I
wonder if your profile/bashrc/or something has a trap entry. But if
that's the case I would guess that the same problem would happen
locally, and not only remotely (unless remote session uses a different
shell or something). Just a W.A.G. :)

Re: [gentoo-user] Ctrl+C not working over ssh?

[Todd Goodman]

* Andy Wilkinson <drukargin@gmail.com> [110524 18:02]:
> On 05/24/2011 12:38 PM, Todd Goodman wrote:
> > * Andy Wilkinson<drukargin@gmail.com>  [110524 12:24]:
> >> I can't say for sure when this started, as I have gone a while without
> >> accessing my computer remotely much, but perhaps since my last upgrade
> >> (which may have included openrc), ctrl-c doesn't work over ssh.  I have
> >> tested this from multiple workstations and even my droid, using
> >> different terminal emulators, and have got consistent results.
> >>
> >> I'm not even sure where to start looking.  Googling didn't find me much
> >> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't
> >> very useful), and I'm not sure at all what might be causing this.  Could
> >> anyone here point me to something that might be causing this?
> >>
> >> Thanks,
> >>
> >> -Andy
> > I don't have any problems.  What does 'stty -a' show for the intr= bit?
> >
> > Todd
> >
> $ stty -a
> speed 38400 baud; rows 23; columns 80; line = 0;
> intr = ^C; ...
> 
> Which looks right, but when I try to use Ctrl-C, this happens:
> 
> $ ping localhost
> PING localhost (127.0.0.1) 56(84) bytes of data.
> 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.037 ms
> ^C64 bytes from localhost (127.0.0.1): icmp_req=2 ttl=64 time=0.032 ms
> ^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=3 ttl=64 time=0.032 ms
> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=4 ttl=64 
> time=0.034 ms
> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=5 ttl=64 
> time=0.032 ms
> ^Z
> 
> This does NOT happen locally: from a console or terminal at the machine, 
> I can interrupt just fine.  Ctrl-Z does//work over ssh.
> 
> Thanks,
> 
> -Andy

Very strange (as someone else said.)

Only thing I can think of is that something in your startup scripts
(.profile, .bashrc, etc.) are doing something different between the
two logins.

I've seen that most often when they do things based on TERM and it's
different between a local login and remote.

Maybe make sure your startup scripts run with a 'set -x' at the
beginning and compare the output?

Good luck,

Todd

Re: [gentoo-user] Ctrl+C not working over ssh?

[Andy Wilkinson]

On 05/25/2011 07:08 AM, Todd Goodman wrote:
> * Andy Wilkinson <drukargin@gmail.com> [110524 18:02]:
>> On 05/24/2011 12:38 PM, Todd Goodman wrote:
>>> * Andy Wilkinson<drukargin@gmail.com>  [110524 12:24]:
>>>> I can't say for sure when this started, as I have gone a while without
>>>> accessing my computer remotely much, but perhaps since my last upgrade
>>>> (which may have included openrc), ctrl-c doesn't work over ssh.  I have
>>>> tested this from multiple workstations and even my droid, using
>>>> different terminal emulators, and have got consistent results.
>>>>
>>>> I'm not even sure where to start looking.  Googling didn't find me much
>>>> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't
>>>> very useful), and I'm not sure at all what might be causing this.  Could
>>>> anyone here point me to something that might be causing this?
>>>>
>>>> Thanks,
>>>>
>>>> -Andy
>>> I don't have any problems.  What does 'stty -a' show for the intr= bit?
>>>
>>> Todd
>>>
>> $ stty -a
>> speed 38400 baud; rows 23; columns 80; line = 0;
>> intr = ^C; ...
>>
>> Which looks right, but when I try to use Ctrl-C, this happens:
>>
>> $ ping localhost
>> PING localhost (127.0.0.1) 56(84) bytes of data.
>> 64 bytes from localhost (127.0.0.1): icmp_req=1 ttl=64 time=0.037 ms
>> ^C64 bytes from localhost (127.0.0.1): icmp_req=2 ttl=64 time=0.032 ms
>> ^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=3 ttl=64 time=0.032 ms
>> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=4 ttl=64 
>> time=0.034 ms
>> ^C^C^C^C^C^C64 bytes from localhost (127.0.0.1): icmp_req=5 ttl=64 
>> time=0.032 ms
>> ^Z
>>
>> This does NOT happen locally: from a console or terminal at the machine, 
>> I can interrupt just fine.  Ctrl-Z does//work over ssh.
>>
>> Thanks,
>>
>> -Andy
> Very strange (as someone else said.)
>
> Only thing I can think of is that something in your startup scripts
> (.profile, .bashrc, etc.) are doing something different between the
> two logins.
>
> I've seen that most often when they do things based on TERM and it's
> different between a local login and remote.
>
> Maybe make sure your startup scripts run with a 'set -x' at the
> beginning and compare the output?
>
> Good luck,
>
> Todd
>
Well, for no good reason, a reboot once I was back at the machine fixed
the issue.  I'm not sure why; I didn't change anything.  I hate not
knowing why reboots fix things. :(

-Andy

Re: [gentoo-user] Ctrl+C not working over ssh?

[Todd Goodman]

* Andy Wilkinson <drukargin@gmail.com> [110525 21:27]:
[...]
> Well, for no good reason, a reboot once I was back at the machine fixed
> the issue.  I'm not sure why; I didn't change anything.  I hate not
> knowing why reboots fix things. :(
> 
> -Andy

Argh!!!  I did see in a google search that someone else had the problem
and a reboot fixed it too.

If it ever happens again I'd wonder if all new SSH sessions experience
the same problem and if so, if restarting the SSH daemon fixes it too.

Or if it's some weirdness with the psuedo-tty system.

Todd

Re: [gentoo-user] Ctrl+C not working over ssh?

[Indi]

On Tue, May 24, 2011 at 07:00:03PM +0200, Andy Wilkinson wrote:
> I can't say for sure when this started, as I have gone a while without 
> accessing my computer remotely much, but perhaps since my last upgrade 
> (which may have included openrc), ctrl-c doesn't work over ssh.  I have 
> tested this from multiple workstations and even my droid, using 
> different terminal emulators, and have got consistent results.
> 
> I'm not even sure where to start looking.  Googling didn't find me much 
> (at least, not much that's current at all; 5 year-old ubuntu bugs aren't 
> very useful), and I'm not sure at all what might be causing this.  Could 
> anyone here point me to something that might be causing this?
> 

Check the sshd settings of the remote machine.

-- 
caveat utilitor
♫ ❤ ♫ ❤ ♫ ❤ ♫ ❤