getting HDD's spin state

hdd-state

#!/usr/bin/bash

DRIVE_ID[0]=/dev/disk/by-id/wwn-0x50014ee2ae42a608 # 2TB   Disk model: WDC WD20EADS-00S
DRIVE_ID[1]=/dev/disk/by-id/wwn-0x50014ee20a7836a8 # 4TB   Disk model: WDC WD40EZRX-00S
DRIVE_ID[2]=/dev/disk/by-id/wwn-0x5000c500b1841369 # 8TB   Disk model: ST8000NM0055-1RM
DRIVE_ID[3]=/dev/disk/by-id/wwn-0x5000c500b1844fe1 # 8TB   Disk model: ST8000NM0055-1RM
DRIVE_ID[4]=/dev/disk/by-id/wwn-0x5000c500b185901f # 8TB   Disk model: ST8000NM0055-1RM

for DRIVE_NUM in "${!DRIVE_ID[@]}"; do   # init some variables
    DRIVE_STATE_OLD[$DRIVE_NUM]=""
    DRIVE_STATE_TIME_CHANGED_OLD[$DRIVE_NUM]=$(( $(date +%s) - 10 ))
    DRIVE_STATE_TIME_CHANGED[$DRIVE_NUM]=$(date +%s)
#    echo "DRIVE_ID[$DRIVE_NUM] = ${DRIVE_ID[$DRIVE_NUM]}"
done

YELLO=$(echo -e "\e[1;33m")
GREEN=$(echo -e "\e[32m")
RED=$(echo -e "\e[31m")
NOCOL=$(echo -e "\e[0m")

echo "$(date '+%Y.%m.%d %H:%M:%S')   started..."
while (true)
do
    DRIVES_CNT_STOPPED=0
    for DRIVE_NUM in "${!DRIVE_ID[@]}"; do
        DRIVE_STATE_DURATION[$DRIVE_NUM]="     "

        DRIVE_STATE[$DRIVE_NUM]=$( smartctl -i -n sleep  ${DRIVE_ID[$DRIVE_NUM]} | grep 'Power'|cut -d: -f2|sed -e 's/^  *//g' -e 's/ /_/g' -e 's/ACTIVE_or_IDLE/Spin/g' -e 's/IDLE_A/Spin/g' -e 's/IDLE_B/Spin/g' -e 's/STANDBY/Stop/g' )
        if [[ ${DRIVE_STATE[$DRIVE_NUM]} == "Stop" ]]; then
            DRIVES_CNT_STOPPED=$(( $DRIVES_CNT_STOPPED + 1 ))                                                                                                           # count number of stopped drives for statistics
        fi

        case ${DRIVE_STATE[$DRIVE_NUM]} in                                                                                                                              # colorize drive state
            Spin)
            DRIVE_STATE_COLORED[$DRIVE_NUM]=$(echo "${YELLO}${DRIVE_STATE[$DRIVE_NUM]}${NOCOL}")
            ;;
            Stop)
            DRIVE_STATE_COLORED[$DRIVE_NUM]=$(echo "${GREEN}${DRIVE_STATE[$DRIVE_NUM]}${NOCOL}")
            ;;
            *)
            DRIVE_STATE_COLORED[$DRIVE_NUM]=${DRIVE_STATE[$DRIVE_NUM]}
            ;;
        esac

        if [[ ${DRIVE_STATE_OLD[$DRIVE_NUM]} != ${DRIVE_STATE[$DRIVE_NUM]} ]] ; then                                                                                    # if that drive's state changed:
            state_change=1                                                                                                                                              # initiate print out after iteration

            DRIVE_STATE_TIME_CHANGED[$DRIVE_NUM]=$(date +%s)                                                                                                            # get change time
            DRIVE_STATE_DURATION[$DRIVE_NUM]=$(printf "%5s" "$(( (${DRIVE_STATE_TIME_CHANGED[$DRIVE_NUM]} - ${DRIVE_STATE_TIME_CHANGED_OLD[$DRIVE_NUM]}) / 60 ))")      # calculate duration since last change
            if [[ ${DRIVE_STATE_OLD[$DRIVE_NUM]} == "Spin" ]]; then                                                                                                     # colorize duration according to last state
                DRIVE_RESULT[$DRIVE_NUM]=$(echo -n "${DRIVE_STATE_COLORED[$DRIVE_NUM]}${YELLO}${DRIVE_STATE_DURATION[$DRIVE_NUM]}${NOCOL}")
            else
                DRIVE_RESULT[$DRIVE_NUM]=$(echo -n "${DRIVE_STATE_COLORED[$DRIVE_NUM]}${GREEN}${DRIVE_STATE_DURATION[$DRIVE_NUM]}${NOCOL}")
            fi
            DRIVE_STATE_TIME_CHANGED_OLD[$DRIVE_NUM]=${DRIVE_STATE_TIME_CHANGED[$DRIVE_NUM]}                                                                            # last change = now
            DRIVE_STATE_OLD[$DRIVE_NUM]=${DRIVE_STATE[$DRIVE_NUM]}                                                                                                      # last state = actual
        else
            DRIVE_STATE_DURATION[$DRIVE_NUM]="     "
            DRIVE_RESULT[$DRIVE_NUM]=$(echo -n "${DRIVE_STATE_COLORED[$DRIVE_NUM]}${DRIVE_STATE_DURATION[$DRIVE_NUM]}")                                                 # add colored state to print out
        fi
    done

    if [[ $state_change -eq 1 ]]; then                                                                                                                                  # print out now?
        state_change=0
        echo -n "$(date '+%Y.%m.%d %H:%M:%S')   "
        for DRIVE_NUM in "${!DRIVE_ID[@]}"; do
            echo -n "${DRIVE_RESULT[$DRIVE_NUM]} - "
        done
        if [[ $DRIVES_CNT_STOPPED -eq ${#DRIVE_ID[@]} ]]; then 
          echo -n " ${RED}YIPPIE YEAH! All stopped!${NOCOL}"
        fi
        echo
    fi
    sleep 1
done