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.
