Hung application in shell

Question

Sometimes when an application hangs in bash session (e.g. network lags in telnet, ssh, whatever) I can't kill it with ^C, stop it with ^D and even send it to background with ^Z.

Is there a way to kill it without opening another shell with kill? I guess there's a syscall to interrupt

score 4 · Accepted Answer · answered Jul 27 '10 at 12:28

4

If you are using SSH, try the two ketstroke combination: ~ ^z (tilde, and then control-z). This will escape out of the SSH session. The same can be done with telnet by pressing ^] (ctrl and then ]).

Now you can start a new session and kill the offending process or the entire session. Is this what you are looking for?

answered Jul 27 '10 at 12:28

jftuga

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Yep, looks like a solution, thank you :) I'll test it ASAP. But is there a more universal solution? Maybe, some 'emergency' hotkey can be mapped in bash that kills the current task? – kolypto Jul 27 '10 at 13:17
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In you ran inside of screen, you could open a new window and then kill the process. – jftuga Jul 27 '10 at 13:46
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@o_O Tync: ^C, ^D and ^Z *are* the emergency hotkeys. – Dennis Williamson Jul 27 '10 at 14:51

score 2 · Answer 2 · answered Jul 29 '10 at 05:14

You can send the process a SIGQUIT with a Ctrl-\ which sometimes works if the process has a signal handler for SIGTERM (Ctrl-c) or SIGSTOP (Ctrl-z).

If your process is blocking on I/O syscalls (ps shows it in state D,) it's in an uninterruptable sleep and you're going to have to wait until the resource it's waiting for starts responding.

Hung application in shell

2 Answers2