Tip: Automatic logout all users when reboot/halt over ssh

CBJ · 2008-06-11 23:09:28

First the why:
OpenSSH on Debian automatically logs out users when you reboot or halt the server over SSH. This is rather nice, as it frees the terminal you ran ssh in for other jobs, instead of just waiting for respond from the server that has gone down.
How they did it I don't know, I have been unable to find any hints on it anyway.

Anyway, OpenSSH on Arch does not act this friendly and a Debian client hang for about 20 min before giving up. Debian's fault I think as an Arch client gives up long before that. Well you don't get it all with Debian...

Then the how:
After searching for a solution I ran into 'skill' that shout do the trick with this string:

# skill -KILL -v pts/*

However, it didn't work...

I could logout each user on his own with:

# skill -KILL -u [user]

But not very helpful either as a solution.
But remembering some sniplet I found on this forum for searching the license-string in installed packages, I made it find the users logged into the system with 'who' and throw them out:

who | cut -d " " -f1 | uniq | xargs skill -KILL -u

If you add this to /etc/rc.local.shutdown it will logout all users before the system goes down due to reboot or halt.
It works quite well on a desktop-system too...

I hope someone finds this helpful.

C

android · 2011-11-18 18:20:59

Thanks CBJ!

This is still working in 11/11 8-)

I added it to the "Tips and Tricks" section of the SSH wiki page: https://wiki.archlinux.org/index.php/Se … s_shutdown

karol · 2011-11-18 18:42:37

Maybe you can do

users | xargs skill -KILL -u

or something like this.

[karol@black ~]$ who
test2    tty2         2011-11-18 19:38
karol    tty1         2011-11-16 23:34
[karol@black ~]$ who | cut -d " " -f1 
test2
karol
[karol@black ~]$ users
karol test2

fsckd · 2011-11-18 19:48:40

man skill wrote:

These tools are probably obsolete and unportable. The command syntax is poorly defined. Consider using the killall, pkill, and pgrep commands instead.

pkill -KILL -u
updated wiki for you

karol · 2011-11-18 20:34:32

fsckd wrote:

man skill wrote:
These tools are probably obsolete and unportable. The command syntax is poorly defined. Consider using the killall, pkill, and pgrep commands instead.
pkill -KILL -u
updated wiki for you

Does it work for you? It does not work for me:

[karol@black ~]$ users
karol test1 test2
[karol@black ~]$ sudo pkill -KILL -u test1 test2
[karol@black ~]$ users
karol test1 test2
[karol@black ~]$ sudo skill -KILL -u test1 test2
[karol@black ~]$ users
karol

fsckd · 2011-11-18 21:07:33

What happens when you do pkill -KILL -u test1 ?

karol · 2011-11-18 21:11:17

fsckd wrote:

What happens when you do pkill -KILL -u test1 ?

It works, but I'm wondering why specifying multiple users does not.

[karol@black ~]$ users
karol test1
[karol@black ~]$ sudo pkill -KILL -u test1
[karol@black ~]$ users
karol

fsckd · 2011-11-18 21:20:14

Who says it does not?

wonder · 2011-11-18 21:34:23

solution is to add in rc.conf NETWORK_PERSIST="yes". the idea is that networking is stopped and it doesn't kill the ssh connections and instead clients will timeout.

graysky · 2011-11-18 21:42:04

:confused:

Is wondering implying that one does NOT need this tweak in /etc/rc.local.shutdown if one sets the NETWORK_PERSIST="yes" in /etc/rc.conf?

wonder · 2011-11-19 08:34:01

exactly

graysky · 2011-11-19 11:44:21

Thanks wonder. I'll edit the wiki page but is there a reason why this isn't an Arch default?

Last edited by graysky (2011-11-19 11:50:18)

Arch Linux

#1 2008-06-11 23:09:28

Tip: Automatic logout all users when reboot/halt over ssh

#2 2011-11-18 18:20:59

Re: Tip: Automatic logout all users when reboot/halt over ssh

#3 2011-11-18 18:42:37

Re: Tip: Automatic logout all users when reboot/halt over ssh

#4 2011-11-18 19:48:40

Re: Tip: Automatic logout all users when reboot/halt over ssh

#5 2011-11-18 20:34:32

Re: Tip: Automatic logout all users when reboot/halt over ssh

#6 2011-11-18 21:07:33

Re: Tip: Automatic logout all users when reboot/halt over ssh

#7 2011-11-18 21:11:17

Re: Tip: Automatic logout all users when reboot/halt over ssh

#8 2011-11-18 21:20:14

Re: Tip: Automatic logout all users when reboot/halt over ssh

#9 2011-11-18 21:34:23

Re: Tip: Automatic logout all users when reboot/halt over ssh

#10 2011-11-18 21:42:04

Re: Tip: Automatic logout all users when reboot/halt over ssh

#11 2011-11-19 08:34:01

Re: Tip: Automatic logout all users when reboot/halt over ssh

#12 2011-11-19 11:44:21

Re: Tip: Automatic logout all users when reboot/halt over ssh

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