Sunday, July 24

Temporary Disabling Bash History

If you want to disable the bash history temporarily or you want to hide some commands, you can use unset HISTFILE command.

[root@linux1 ~]# unset HISTFILE

The result is that while the session is active you can access the history as usual, but it won’t be saved to the disk. As soon as you exit the session, history will be clear for that particular session only. History for other sessions, will behave as usual.

  609  history
  610  unset HISTFILE
  611  more /etc/passwd |grep splunk
  612  chage -l splunk
  613  history
  614  date
  615  history
[root@linux1 ~]#

Exit from the session and login again - use history command to verify:
609  history
[root@linux1 ~]#

Note: below command will same as unset HISTFILE command
[root@linux1 ~]# HISTFILE=/dev/null

Location of history file.
# echo $HISTFILE

HISTSIZE is the number of lines or commands that are stored in memory in a history list while your bash session is ongoing.
HISTFILESIZE is the number of lines or commands that (a) are allowed in the history file at startup time of a session, and (b) are stored in the history file at the end of your bash session for use in future sessions.

# echo $HISTSIZE
# echo $HISTFILESIZE

# history -c