Just for info: Never do a "wipe -r .*"

Hi all,

just occured the following:

On one of my Linux notebooks, here Mandriva 2009.1, I had to wipe some
files with wipe version wipe-2.2.0-7mdv2009.1 out of the official
repository.

In /tmp I tried to wipe out some users' "dotted" directories, like /
tmp/.wine* using the syntax known from rm:

[ /tmp]$ wipe -r .*

Unlike rm wipe does NOT stop after erasing the files in the current
directory, but instead it jumps to / and continues there.

Though ".." fits the "-r .*" search pattern, everyone familiar with the
rm -rf syntax and behaviour may recursively "wipe" the whole partition,
resulting in a no longer usable system.

It is very annoying, now to see that even in 2001 there were bug reports
created about this item:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug1583

In the meantime I verified this on a different box using a "throwaway
account" (the box mentioned above needs to be reinstalled) and wipe
erases everything in the current directory as desired, and then goes
through / into /home and continues its destrucive task. As seen before.

- Be careful with wipe -

Best regards,

Markus

On 2010-09-04, Markus R. Ke?ler wrote:

Hi all,

just occured the following:

On one of my Linux notebooks, here Mandriva 2009.1, I had to wipe some
files with wipe version wipe-2.2.0-7mdv2009.1 out of the official
repository.

In /tmp I tried to wipe out some users' "dotted" directories, like /
tmp/.wine* using the syntax known from rm:

[ /tmp]$ wipe -r .*

Unlike rm wipe does NOT stop after erasing the files in the current
directory, but instead it jumps to / and continues there.

Of course. That was what you told it to do. Bash ( not wipe) expands
that * and feeds
wipe -r .. . .wine .bashrc
so there it is, you tell it to wipe .. which is the parent directory.
Please learn how bach expands globs.

Though ".." fits the "-r .*" search pattern, everyone familiar with the
rm -rf syntax and behaviour may recursively "wipe" the whole partition,
resulting in a no longer usable system.

It is very annoying, now to see that even in 2001 there were bug
reports created about this item:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug1583

In the meantime I verified this on a different box using a "throwaway
account" (the box mentioned above needs to be reinstalled) and wipe
erases everything in the current directory as desired, and then goes
through / into /home and continues its destrucive task. As seen before.

- Be careful with wipe -

Am Sat, 04 Sep 2010 20:26:41 +0000 schrieb unruh:

On 2010-09-04, Markus R. Ke?ler wrote:

Hi all,

just occured the following:

On one of my Linux notebooks, here Mandriva 2009.1, I had to wipe some
files with wipe version wipe-2.2.0-7mdv2009.1 out of the official
repository.

In /tmp I tried to wipe out some users' "dotted" directories, like /
tmp/.wine* using the syntax known from rm:

[ /tmp]$ wipe -r .*

Unlike rm wipe does NOT stop after erasing the files in the current
directory, but instead it jumps to / and continues there.

Of course. That was what you told it to do. Bash ( not wipe) expands
that * and feeds
wipe -r .. . .wine .bashrc
so there it is, you tell it to wipe .. which is the parent directory.
Please learn how bach expands globs.

Though ".." fits the "-r .*" search pattern, everyone familiar with the
rm -rf syntax and behaviour may recursively "wipe" the whole partition,
resulting in a no longer usable system.

It is very annoying, now to see that even in 2001 there were bug
reports created about this item:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug1583

In the meantime I verified this on a different box using a "throwaway
account" (the box mentioned above needs to be reinstalled) and wipe
erases everything in the current directory as desired, and then goes
through / into /home and continues its destrucive task. As seen before.

- Be careful with wipe -

I said that the pattern matches, or in other words, the shell translates
it to "..". You're right - so far, but not farther.

What I also explained is that people which are used to work with the rm
command in any constellation would, by instinct, assume, that wipe
behaves in the same way. But it does NOT. The rm command in some way
"catches" such patterns and excludes them from the parameters it gets
from the shell. - Wipe does not.

That's the point.

On 2010-09-04, Markus R. Keßler wrote:

Am Sat, 04 Sep 2010 20:26:41 +0000 schrieb unruh:

On 2010-09-04, Markus R. Ke?ler wrote:

Hi all,

just occured the following:

On one of my Linux notebooks, here Mandriva 2009.1, I had to wipe some
files with wipe version wipe-2.2.0-7mdv2009.1 out of the official
repository.

In /tmp I tried to wipe out some users' "dotted" directories, like /
tmp/.wine* using the syntax known from rm:

[ /tmp]$ wipe -r .*

Unlike rm wipe does NOT stop after erasing the files in the current
directory, but instead it jumps to / and continues there.

Of course. That was what you told it to do. Bash ( not wipe) expands
that * and feeds
wipe -r .. . .wine .bashrc
so there it is, you tell it to wipe .. which is the parent directory.
Please learn how bach expands globs.

Though ".." fits the "-r .*" search pattern, everyone familiar with the
rm -rf syntax and behaviour may recursively "wipe" the whole partition,
resulting in a no longer usable system.

It is very annoying, now to see that even in 2001 there were bug
reports created about this item:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug1583

In the meantime I verified this on a different box using a "throwaway
account" (the box mentioned above needs to be reinstalled) and wipe
erases everything in the current directory as desired, and then goes
through / into /home and continues its destrucive task. As seen before.

- Be careful with wipe -

I said that the pattern matches, or in other words, the shell translates
it to "..". You're right - so far, but not farther.

What I also explained is that people which are used to work with the rm
command in any constellation would, by instinct, assume, that wipe
behaves in the same way. But it does NOT. The rm command in some way
"catches" such patterns and excludes them from the parameters it gets
from the shell. - Wipe does not.

That's the point.

Suggestions for safety's sake:

If you want to specify the dot files but avoid picking up
. and .. one trick is to specify '.??*' (without the
quotation marks). That will miss any dot files with only one
character after the dot, but those are very rare.

When working with a potentially dangerous command, first do
'du' or 'file' or something benign on the argument your are
thinking of using. If that gets the right set of files,
_THEN_, _CAREFULLY_, do the dangerous command and specify !$
or !* or something similar.

HTH

Am Sun, 05 Sep 2010 03:55:39 +0000 schrieb Robert Riches:

On 2010-09-04, Markus R. Keßler wrote:

Am Sat, 04 Sep 2010 20:26:41 +0000 schrieb unruh:

On 2010-09-04, Markus R. Ke?ler wrote:

Hi all,

just occured the following:

On one of my Linux notebooks, here Mandriva 2009.1, I had to wipe some
files with wipe version wipe-2.2.0-7mdv2009.1 out of the official
repository.

In /tmp I tried to wipe out some users' "dotted" directories, like /
tmp/.wine* using the syntax known from rm:

[ /tmp]$ wipe -r .*

Unlike rm wipe does NOT stop after erasing the files in the current
directory, but instead it jumps to / and continues there.

But even other commands, like "find" behave like "rm":

/*

[1004 tmp]$ find . -iname '.*'
.
./.wine-dimke
./.ICE-unix
./.font-unix
./.X11-unix

*/

So, the worst thing that could theoretically happen here is that the whole
/tmp would be erased, but NOT the parent directory if you do a "cd /tmp ;
find . -iname '.*' | xargs rm -rf".

The reason why I wrote the original message is, that people likely assume
"wipe" to behave similarly to "rm", including myself.
And this is not the case.