bash animation function

showanim

# tar zxf big_file.tar.gz > /dev/null 2>&1 &
# printf "%s" "[+] tar is running ..." && _animcui $(pidof tar)

showanim()
{
    [ -z "$1" ] && { printf "%5s\n" ""; return 1; }
    printf "%s\\n" "$1" | grep -v "[^0-9]" >/dev/null || { printf "%5s\n" ""; return 1; }
    _animcui_var_pid="$1"
    _animcui_var_animation_state=1

    if [ ! "$(ps -p $_animcui_var_pid -o comm=)" ]; then
        printf "%5s\n" ""
        return 1
    fi

    printf "%s" "      "

    while [ "$(ps -p $_animcui_var_pid -o comm=)" ]; do
        printf "%b" "\b\b\b\b\b"
        case $_animcui_var_animation_state in
            1)
                printf "%s" '\o@o\'
                _animcui_var_animation_state=2
                ;;
            2)
                printf "%s" '|o@o|'
                _animcui_var_animation_state=3
                ;;
            3)
                printf "%s" '/o@o/'
                _animcui_var_animation_state=4
                ;;
            4)
                printf "%s" '|o@o|'
                _animcui_var_animation_state=1
                ;;
        esac
        sleep 1
    done
    printf "%b" "\b\b\b\b\b" && printf "%5s\n" ""
}