bash-history.sh

# say we start with an empty bash command history
bash-3.2$ history
    1  history


# enter a command that requires a password
bash-3.2$ sudo rm -i some_file
Password:
# accidentally ^C and type your password
# into the prompt and hit enter
bash-3.2$ secret_password
bash: secret_password: command not found


# your password is now there for all to
# see in your bash history
bash-3.2$ history
    1  history
    2  sudo rm -i some_file
    3  secret_password
    4  history


# first option to fix it, delete the numbered entry from
# history and write to your ~/.bash_history file
bash-3.2$ history -d 3
bash-3.2$ history -w


# entry 3 will be removed entirely from your command history
bash-3.2$ history
    1  history
    2  sudo rm -i some_file
    3  history
    4  history -d 3
    5  history -w
    6  history


# the second option is to clear the entire history
# and write the changes to disk
bash-3.2$ history -c
bash-3.2$ history -w


# it's now pretty obvious that your history has been
# scrubbed clean, but at least your password is history!
bash-3.2$ history
    1  history -w
    2  history