ubuntu: destroy a huge binary file and make it non-readable.

[Johnny Rosenberg]

2014-01-25 ping song <songpingemail at gmail.com>

> thanks.
> but guess I haven't make it clear.
>
> my goal is to :
> 1) not to delete the file, not to chmod either
> 2) don't change the file size either
> 3) make the gzip file not being able to ungzipped and viewed - just to
> mess up the file and make it not usable (what I meant "destroy").
>
> I finally use GNU "head" to delete the last a couple of lines like this:
>
> head --lines=-100 myfile.gz > newfile.gz
>
> after this , gzip can't recogize it. that's it.
>
> but , I doubt this is not the safe way, coz an gzip expert might be easily
> open the binary file and fixed the missed lines (I'm not sure).
>
> maybe I better 'sort' the whole file, or, swap randomly some lines, so
> there is no way the file can be read...
>


I know this is way off topic, but I'm just curious: Why do you want to do
this? Is the file ever going to be readable again? If not, why not just
delete it…? If you want to be able to open the file yourself but nobody
else, why not just protect it (encrypt it) with a password?

Johnny Rosenberg


>
>
> On Sat, Jan 25, 2014 at 12:09 PM, Liam Proven <lproven at gmail.com> wrote:
>
>> On 25 January 2014 16:17, ping song <songpingemail at gmail.com> wrote:
>> > may sounds like a sin, but I just wanna know the best way to change a
>> binary
>> > file without actually open it (since it's really huge)?
>>
>> Your subject says "destroy". To me that would seem to mean securely erase.
>>
>> But your body text seems to ask about editing it.
>>
>> As such, I do not understand what you mean.
>>
>> If you do mean secure erase, read this:
>>
>> http://askubuntu.com/questions/57572/how-to-delete-files-in-secure-manner
>>
>>
>> --
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>>
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