I remember doing a fresh install of unix on a VAX with another sysadmin. We had spent a couple hours getting everything ready to go, and he had created a bunch of temporary directories under /tmp to hold intermediate work. All started with ".", so, in /tmp, he entered "rm -r .*". Unfortunately, that matched .. as well. We knew something had gone very wrong when we got a "/bin/rm: text busy" message as rm tried to remove itself.

On Thu, Aug 30, 2018 at 7:06 AM, <ron@ronnatalie.com> wrote:
I use the numbers but I think it stems from the days when kill didn't take
the names.    It's easier for me to remember -1 and -9 than to remember what
the mnemonics are.

> -----Original Message-----
> From: TUHS <tuhs-bounces@minnie.tuhs.org> On Behalf Of Dave Horsfall
> Sent: Wednesday, August 29, 2018 6:04 PM
> To: The Eunuchs Hysterical Society <tuhs@tuhs.org>
> Subject: Re: [TUHS] Cryptic Unix Commands
> On Wed, 29 Aug 2018, Warren Toomey wrote:
> > This reminded me of other semi-cryptic commands. I remember mistyping
> > "kill -1 1" as "kill -9 1" with the inevitable consequences.
> Hands up all those who have *not* done that...
> -- Dave