fancyprompt.sh

      __set_prompt()
      {
        test "$PS_ORIG" || PS_ORIG="$PS1"
        test "$PC_ORIG" || eval "PC_ORIG='$PROMPT_COMMAND'"
        PROMPT_COMMAND=__bash_prompt
      }; readonly -f __set_prompt
      __bash_prompt()
      {
        local ERRORLEVEL=$?
        if [ $ERRORLEVEL != 0 ]; then
          ERRORLEVEL="\n[$(tput setaf 1)$ERRORLEVEL$(tput sgr0)]"
        else
          ERRORLEVEL=
        fi

        eval "$PC_ORIG"
        [ "$PS_ORIG" ] && PS1="$ERRORLEVEL$PS_ORIG"
      }; readonly -f __bash_prompt