Bash / VIM private mode

.bashrc

function upsearch () {
    dir="${PWD}"
    while true
    do
        [[ -f "${dir}/${1}" ]] && return 0
        [[ "${dir}" == '/' ]] && return 1
        dir=$(dirname "${dir}")
    done
}
function update_window_title() {
    [[ ${1} == ${FUNCNAME} ]] && return
    title="${1}"
    [[ $PRIVATE == 1 ]] && title="[PRIVATE]${title:+ $title}"
    echo -ne "\033]0;${title}\007"
}
alias private='unset HISTFILE && export PS1="\e[4;36m[PRIVATE]\e[m \h:\W \u\$ " && export PRIVATE=1'
alias vimprivate='( PRIVATE=1 vim ; history -d $((HISTCMD-1)) )'
PROMPT_COMMAND="$(echo $PROMPT_COMMAND | sed 's/\s*;\s*$//g')"PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND ; }"'upsearch ".private" && private ; update_window_title "$(basename ${SHELL})"'
trap 'update_window_title "${BASH_COMMAND%% *}"' DEBUG
upsearch '.private' && private

.vimrc

if $PRIVATE == 1
  set viminfo+=n/dev/null
  set noswapfile
  set nobackup
     
  set laststatus=2
  highlight StatusLine NONE ctermbg=LightBlue ctermfg=Black cterm=bold
  highlight StatusLineNC NONE ctermbg=DarkBlue ctermfg=White cterm=NONE
  set statusline=[PRIVATE]\ %<%f\ %h%m%r%=%-14.(%l,%c%V%)\ %P
endif