How to disable command prompt history?

[sac]

On 6/2/07, Christopher Hilton <chris at vindaloo.com> wrote:
> VeeJay wrote:
> > Hello there
> >
> > Could someone would like to describe that how we can disable to show last
> > executed commands by pressing Up Arrow?
> >
>
> That would depend on which shell you are running. Can you run the
> following command and post the results here?
>
>      echo $SHELL
>

By default most of the shells like bash, zsh, ksh have history option.
But you can avoid writing the history of the current session to the
history file by unsetting the HISTFILE environment variable.
So next time when you login the history of the previous session will
not be shown.

sac.