You can do HISTFILESIZE=0. That way the .bash_history file is never written to, but you can still get the history that's in memory. If you write it to disk, it

You can do HISTFILESIZE=0. That way the .bash_history file is never written to, but you can still get the history that's in memory. If you write it to disk, it could available on the disk via an undelete tool or via a backup - which is a concern if you ever accidentally paste a password onto the command line.