Homebridge disk space as Humidity Sensor with homebridge-cmd4 plugin

DiskSpaceHumiditySensor.sh

#!/usr/bin/env bash

# Plugin: https://github.com/ztalbot2000/homebridge-cmd4
#
# config.json
#
#  ...
#  {
#     "platform": "Cmd4",
#     "name": "Cmd4",
#     "accessories":
#     [
#         {
#           "type": "HumiditySensor",
#           "name": "Disk Space",
#           "currentRelativeHumidity": 1,
#           "statusActive": 1,
#           "statusFault": 0,
#           "statusTampered": 0,
#           "statusLowBattery": 0,
#           "stateChangeResponseTime": 0,
#           "state_cmd": "bash .homebridge/Cmd4Scripts/DiskSpaceHumiditySensor.sh"
#         }
#     ]
#  }
#  ...

if [ "$1" = "Get" ]; then
    case $3 in
        "StatusFault" | "StatusTampered" | "StatusLowBattery")
            echo 0
            exit 0
            ;;
        "StatusActive")
            echo 1
            exit 0
            ;;
        "CurrentRelativeHumidity")
            diskSpace=$(df -Bm | sed '2q;d' | sed 's/.*\([0-9][0-9]\%\).*/\1/' | sed s/\%//)
            echo "$diskSpace"
            exit 0
            ;;
    esac
fi

exit -1