Re: history issue - bug?
On Sun 14 Jan 2018 at 17:46:51 (+0100), Hans wrote:
> 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. 
Sorry, but that wouldn't be how the English in that statement would
normally be understood.
> And as far as I remember, this did it do in former times. 
Not in bash 2.
> 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. 
If this concerns you, truncate ~/.bash_history and chmod a=r.
> As I said, history -c should delete ALL traces of history, just as the help 
> files tells, shouldn't it?
No. you lose functionality.
> As you confirmed, it does not and you also 
> confirmed, that this is normal behaviour. 
Yes, and it follows the documentation.
> In this case, I recommend this as a failure-by-design.
> Again, thanks for your clearence, I will file a bug report.
I would prefer you didn't.
> > 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.
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