Run command in bash without save in history

Question

How to run command in bash without saving it in history?

Answer 1

Add space before command. commands starting with a space do not put in history:

root@ubuntu-1010-server-01:~# echo foo
foo
root@ubuntu-1010-server-01:~# history 
    1  echo foo
    2  history 
root@ubuntu-1010-server-01:~#  echo bar
bar
root@ubuntu-1010-server-01:~# history 
    1  echo foo
    2  history 

man bash

  HISTCONTROL
         A  colon-separated  list of values controlling how commands are
         saved on the history list.  If  the  list  of  values  includes
         ignorespace,  lines  which begin with a space character are not
         saved in the history list.  A value of ignoredups causes  lines
         matching  the  previous history entry to not be saved.  A value
         of ignoreboth is shorthand for ignorespace and  ignoredups.   A
         value  of erasedups causes all previous lines matching the cur‐
         rent line to be removed from the history list before that  line
         is  saved.   Any  value  not  in the above list is ignored.  If
         HISTCONTROL is unset, or does not include a  valid  value,  all
         lines  read  by the shell parser are saved on the history list,
         subject to the value of HISTIGNORE.  The second and  subsequent
         lines  of a multi-line compound command are not tested, and are
         added to the history regardless of the value of HISTCONTROL.

Answer 2

Also worth mentioning the trick to kill the current login session instead of normal exit (thus not giving a chance to save the history). This is especially useful when you login to a shared a/c, instead of remembering to prefix with a space, you could just end the session by killing it. The simplest way to kill is by running this command:

kill -9 0

Pid 0 always refers to the current process's PID, so you are basically sending a deadly kill signal to itself. I also often use this instead of exiting normally, as I often have hung sessions on normal exit, probably due to some misconfiguration.

Answer 3

Another solution is to set the history file to a directory:

export HISTFILE=/