[patch] rm can have undesired side-effects

[Joerg Pernfuss]

On Sun, 29 Oct 2006 23:28:47 +0100
Romain Tartiere <romain-tartiere at astase.com> wrote:

> The rm utility provides a "-P" option for overwriting files before
> removing them. I was wondering about the behaviour of it on regular
> files with more than one hard link.
> I just wrote a few lines in a file, created an hard link to it and "rm
> -P" the first one. The content of the second one was just lost too.

Of course. It is the same file. Every other outcome would indicate
a serious bug somewhere in the filesystem code.

> I guess that it can be fixed (in case it is not desired) by:
>  - Ignoring the -P option when the link count is greater then one, or

Silently ignoring user specified options is seldom a good way to go.
The user explicitly stated he wants to wipe the file contents.

>  - Asking the user whether he is ready to lose data, assuming "no" if
>    the -f option is set, or
>  - Asking the user whether he is ready to lose data, assuming "yes" if
>    the -f option is set.

As -f is the `i know how to shoot my feet' option, a user should be
allowed to do so, therefor the second one of these two is better.

I guess it boils down to the question how well people understand the
linkcount in `ls -l' and how much FreeBSD wants to hold the user's hand.

Personally, i'd go nuts if rm(1) constantly asks if I am sure I want
to delete that file, because deleted files are lost. If I ever want
that, I can set `rm -i' as alias for rm.

	Joerg
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