Re: /dev/null > /dev/sdb1 !
On 2008-04-22 15:45 +0200, Matthew Macdonald-Wallace wrote:
> On Tue, 22 Apr 2008 21:35:31 +0800
> paragasu <paragasu@gmail.com> wrote:
>
>> now i am wondering. whether it is because the command i just executed
>> or my hard disk is really dying?
>
> It could be either. The command you typed effectively formatted the
> disk.
I don't think so.
> /dev/null contains no data. It is the Linux equivalent of a black
> hole. If you send the output of /dev/null to a file (which is exactly
> what you have done) with a single chevron (>), it will overwrite
> anything that exists in that file (in this case the entire contents of
> your disk).
Only true for an ordinary file and because it's the shell that truncates
the file before the redirection. Since you cannot read anything from
/dev/null, catting it to device files is harmless. It's a different
story with /dev/zero instead of /dev/null ...
> If you use a double chevron (>>) you will append the
> contents of /dev/null to the end of the file (in this case, your disk).
But because you append nothing, that's actually a no-op.
Sven
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