Delete BASH history on exit for all users

Question

Using Red Hat Enterprise Linux is it possible to place a global option that whenever a user exits an SSH connection the BASH history for that user is cleared?

Bourgeoisie

There's not much you can do if the users have customized their bash session to save their history in an arbitrary file. – Polynices

Try setting /etc/bash.bash_logout as I suggest in my answer. – Emiliaemiliaromagna

None of the below suggested answers work. – Bourgeoisie

Answer 1

In the /etc/bash.bash_logout script you can put:

unset HISTFILE

The default for HISTFILE is ~/.bash_history. The user can set this to whatever they wish. If it's not set, the logout process doesn't write the history information that's in RAM to the history file.

Emiliaemiliaromagna

This would only clear the in-memory history, which doesn't persist after the shell exits anyway. – Polynices

See my answer. There's no guarantee that .bash_history is used to store the history. – Polynices

bash does not have a global logout file by default, although it appears you can enable it at compile time. I don't know if that is executed before or after ~/.bash_logout where available. – Polynices

@Polynices I have a fairly "default" installation of Fedora 18 and /etc/bash.bash_logout is operational on my system. I didn't compile the system myself. – Emiliaemiliaromagna

Looks like it's disabled in the bashs installed on my Mac OS X box, but is enabled on one of my Linux boxes at work. It also appears (which you have probably confirmed) that it is sourced after the user's logout file. – Polynices

HOWEVER, :), the user could always make sure his history is written out before the global file unsets HISTFILE. – Polynices

@Polynices yep, I agree, the ultimate "cheat" would be that the user could run the history command into some arbitrary file then copy it back over after they login. – Emiliaemiliaromagna

Answer 2

Put the following in ~/.bash_logout

echo > $HISTFILE

This will erase the saved history for a user at logout, but will keep a useful running history when user is logged-in.

Meilhac

Answer 3

I know you can manually run

history -c

I think you can put this into your ~/.bash_logout.

Creature

Answer 4

The user can always save their history to a non-standard file and reload it on the next login, so their isn't much you can do from a global standpoint to stop it.

For example, Bob might put the following in his ~/.bash_login:

HISTFILE=~/my_secret_history_file

Polynices

Is it possible globally to set history to /dev/null or something? – Bourgeoisie

No, because the user configuration files are sourced after the global ones. The best you can do is set a policy that history cannot be stored, but there's no technical way to enforce such a policy. – Polynices

Answer 5

When needed to let the histories empty - I use symlinking them to /dev/null...

lrwxrwxrwx  1 root root    9 Dez 16 19:10 .ash_history -> /dev/null
lrwxrwxrwx  1 root root    9 Dez 16 19:10 .bash_history -> /dev/null

...then the history of typed commands work only for current session.
Starting a new shell, starting a new empty temporary history.
Symlinking them for normal users to /dev/null have to be done by: root

Hallucination