How to disable command prompt history?

['Anubhav A.']

in message
<e14997e00706021056h2c94e1c6je3e57acc33841066 at mail.gmail.com>, wrote
sac thusly...
>
> > VeeJay wrote:
> > >
> > > Could someone would like to describe that how we can disable
> > > to show last executed commands by pressing Up Arrow?
...
>  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.

Perhaps so, but to me it seems that OP was asking to turn off the
history recall in the current session itself.  In bash & zsh,
setting HISTSIZE may be of some value.


  - Parv

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