Re: history issue - bug?

[Hans <hans.ullrich@loop.de>]

Am Sonntag, 14. Januar 2018, 08:41:21 CET schrieb David Wright:
Hi David,

thanks for enlightening me. I always though, that "history -c" would clear all 
the history and its files as the help file says:

-c        clear the history list by deleting all of the entries

So IMO this should delete all related history files, even bash_history. 

And as far as I remember, this did it do in former times. 

In my eyes this is a security hole, as someone, who gaines root somehow (what 
already is bad eneough) might get more informations of commands, root did in 
the past. 

As I said, history -c should delete ALL traces of history, just as the help 
files tells, shouldn't it? As you confirmed, it does not and you also 
confirmed, that this is normal behaviour. 

In this case, I recommend this as a failure-by-design.

Again, thanks for your clearence, I will file a bug report.

Best 

Hans
> On Sun 14 Jan 2018 at 14:07:01 (+0100), Hans wrote:
> > Hi folks,
> > 
> > try this:
> > 
> > 1. login as normal user
> > 
> > 2. become root with "su -"
> 
> … which reads ~/.bash_history into what I call the command recall buffer.
> 
> > 3. delete history with "history -c"
> 
> … which deletes all the entries in the recall buffer, those just read
>   in and those commands typed since logging in.
> 
> > 4. Check history, history is gone
> 
> Presumably you mean you just tried to recall a command and failed.
> Make that command "ls -l ~/.bash_history" and you'll see the file
> is still there.
> 
> > 5. logout from root by "CTL + D" or "exit"
> > 
> > 6. relogin as root with "su -"
> 
> … which reads ~/.bash_history.
> 
> > 7. Check history, voila, it appears again.
> 
> … as expected.
> 
> > What is wrong?
> 
> Distinguish between history list and history file.
> 
> To eliminate your history, you need to remove/empty the file and
> also clear the list just before you logout.
> 
> Cheers,
> David.