rotating animation for bash

gistfile1.txt

# Usage: 
#   printf "%s" "[+] tar" && _animrotate $(pidof tar)
#


animrotate()
{   #shows an animation as long as a process is in memory
    [ -z "$1" ] && return 1
    printf "%s\\n" "$1" | grep -v "[^0-9]" >/dev/null || { printf "%5s\n" ""; return 1; }
    _animrotate_var_pid=$1
    _animrotate_var_animation_state=1

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

    printf "%s" "    "

    while [ "$(ps -p $_animrotate_var_pid -o comm=)" ]; do
        # rotating star
        printf "%b" "\b\b\b"
        case $_animrotate_var_animation_state in
            1)
                printf "%s" "["
                printf "%b" "\033[1m|\033[0m"
                printf "%s" "]"
                _animrotate_var_animation_state=2
                ;;
            2)
                printf "%s" "["
                printf "%b" "\033[1m/\033[0m"
                printf "%s" "]"
                _animrotate_var_animation_state=3
                ;;
            3)
                printf "%s" "["
                printf "%b" "\033[1m-\033[0m"
                printf "%s" "]"
                _animrotate_var_animation_state=4
                ;;
            4)
                printf "%s" "["
                printf "%b" "\033[1m"
                printf "%s" "\\"
                printf "%b" "\033[0m"
                printf "%s" "]"
                _animrotate_var_animation_state=1
                ;;
        esac
        sleep 0.2
    done
    printf "%b" "\b\b\b\b\b\b\b       "
}