Why kill -9 -1 doesn't work?

Question

From man kill:

kill -9 -1

Kill all processes you can kill.

But when I do sudo /bin/kill -9 -1 nothing happens.

My uname -a for info:

Linux michal-Q530 3.16.0-45-generic #60~14.04.1-Ubuntu SMP Fri Jul 24 21:16:23 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

And I'm on Lubuntu.

UPDATE:

$ ps -e | wc -l
169
$ sudo /bin/kill -9 -1
$ ps -e | wc -l
169

My man page says kill -s signal .... Have you tried that? – ott-- Aug 04 '15 at 16:47 — ott--, Aug 04 '15 at 16:47

score 3 · Accepted Answer · answered Aug 04 '15 at 18:43

3

Finally solved by using this:

sudo /bin/kill -9 -- -1

If the first PID is negative, it has to be preceded by -- so it's not interpreted as an option.

So the real behavior of /bin/kill is distinct from the behavior described in the man page.

answered Aug 04 '15 at 18:43

MichalH

Ok, I missed that in the man page: kill [-s signal|-p] [--] pid... – ott-- Aug 04 '15 at 18:49
Does sudo kill -9 -1 work? – cuonglm Aug 04 '15 at 18:51
@cuonglm it doesn't work for me. I have tried it on both bash and dash. – MichalH Aug 04 '15 at 18:51
@Mike: sudo /bin/kill -9 -1 work for me on Fedora and CoreOS. – cuonglm Aug 04 '15 at 18:57
It seems to be a bug, what is your util-linux version? – cuonglm Aug 04 '15 at 19:25
2.20.1-5.1ubuntu20.4 – MichalH Aug 04 '15 at 19:31

1 Answers1