ck from the end of the history list
    
      -a	append history lines from this session to the history file
      -n	read all history lines not already read from the history file
    		and append them to the history list
      -r	read the history file and append the contents to the history
    		list
      -w	write the current history to the history file
    
      -p	perform history expansion on each ARG and display the result
    		without storing it in the history list
      -s	append the ARGs to the history list as a single entry
    
    If FILENAME is given, it is used as the history file.  Otherwise,
    if HISTFILE has a value, that is used, else ~/.bash_history.
    
    If the HISTTIMEFORMAT variable is set and not null, its value is used
    as a format string for strftime(3) to print the time stamp associated
    with each displayed history entry.  No time stamps are printed otherwise.
    
    Exit Status:
    Returns success unless an invalid option is given or an error occurs.