Sometimes it is very useful to delete / remove Bash history partially or completely when log out. Here is my favourite methods howto log out / quit / exit Bash shell without saving Bash history.
Remove Only Current Session Bash History and Leave Older History Untouched
1. Quit Bash Shell Without Saving History: Unset HISTFILE
unset HISTFILE && exit
2. Quit Bash Shell Without Saving History: Kill Console
kill -9 $$
Remove/Delete Bash History Completely
3. Quit Bash Shell Without Saving History: Clear History Option
history -c && exit
4. Quit Bash Shell Without Saving History: Set HISTSIZE to 0 (zero)
HISTSIZE=0 && exit
5. Quit Bash Shell Without Saving History: Delete HISTFILE and Unset HISTFILE
rm -f $HISTFILE && unset HISTFILE && exit
If you want make these commands more permanent then these commands could be added on ~/.bash_logout file or used with aliases.