Synopsis:
   set history_file [<filename>]

Description:
   If this variable is set, the client will (attempt to) write out the
   command history to the given file.  It will also read the history from
   this file.  This has the advantage of keeping the client's memory
   usage to a minimum, but it can slow performance.

   This feature can be disabled by unsetting the variable, or setting it
   to "<empty>".  The HISTORY setting must also be disabled to completely
   disable command history.

See Also:
   bind(4) backward_history, forward_history, shove_to_history;
   history(4); set(4) history

Other Notes:
   Setting HISTORY_FILE to /dev/null is not recommended, as the behavior
   is, at best, undefined, due to the various ways different Unixes handle
   reads from and writes to the device.