Protection from the dreaded "rm -fr /"

[Jacques A. Vidrine]

On Sat, Oct 02, 2004 at 10:43:49PM +1000, Peter Jeremy wrote:
> I've had a customer write a cronjob that did almost exactly this.
> He managed to 'test' it on all the (redundant) production systems
> as well as the test model.  We were only called in when he found
> that there were some unexpected console messages and the systems
> wouldn't boot when he pressed the reset button.  Luckily it
> managed to kill itself before it destroyed all the evidence (since
> the culprit initially denied doing anything).
> 
> Based on that, I'm definitely in favour of some anti-foot-shooting
> measures.
[...]

FWIW, I'm not in favor of adding ad-hoc "features" to handle edge-cases.
("feature" because this is actually introducing a bug :-)

I picked this email to which to respond, because I can share my own
stupidity.  Case much like the one described above, but my cronjob
included something like:

    cd /path/to/directory/with/temporary/files
    rm -fr *

Only another admin removed
`/path/to/directory/with/temporary/files'... so the `cd' failed
and left the current directory as `/'.  For some reason the system
crashed :-) ... and then crashed again a few days after restoring
from backup... doh!


Will the next step be to prevent `rm -fr *' iff the current working
directory is '/' ?  Please explain your answer.  :-)

Cheers,
-- 
Jacques A Vidrine / NTT/Verio
nectar at celabo.org / jvidrine at verio.net / nectar at FreeBSD.org