Computational complexity of rm & ls

Rahul Dhesi dhesi at bsu-cs.UUCP
Wed Mar 15 09:34:43 AEST 1989


In article <1280 at itm.UUCP> danny at itm.UUCP (Danny) writes
[about cleaning up runaway directories]:

>    The best "stragety" (thanks, Bugs) I've ever heard of is:
>        use clri to zap the directory,
>        and fsck to clean up the mess.

VAX/VMS has a consistent command structure and the switch /nodirectory
always, always means "not a directory".

Therein lies a tale.

There is a command "set file" that does many things to files, and it
accepts many options while doing those things.

The manual documented "set file/nodirectory" to mean "act on these
files only if they aren't directories", but the command interpreter
understood it to mean "make sure these aren't directories."  So if you
did

     $ set file/nodirectory *.*

all subdirectories matching *.* suddenly became regular files.  In
effect, we had a command that was (a) accessible to ordinary users and
(b) documented to be harmless but (c) did a near-clri on specified
directories.

Unfortunately, the same unprivileged users couldn't do the equivalent
of fsck (analyze/disk or something like that).

I think they fixed it.  I didn't try it again.
-- 
Rahul Dhesi         UUCP:  <backbones>!{iuvax,pur-ee}!bsu-cs!dhesi
                    ARPA:  dhesi at bsu-cs.bsu.edu



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