Poweroff or poweron usb devices in Linux

Sometimes, I need my external drive to suspend/spin down when I am suspending my machine.

Use lsusb to replace the vendor/product ids.

In my case

$ lsusb

...

Bus 001 Device 008: ID 1058:0704 Western Digital Technologies, Inc. Passport External HDD

...

~/bin/poweroff-usbdisk.sh

#!/bin/sh
# Poweroff a device identified by the vendor/product id below.
# If you have two similar devices (e.g two western digital drives),
# the script will fail. The fix is easy: enumerate the devices
# and suspend them individually. 

vendorid=1058
productid=0704

# Look for western digital
USBDIR=$(dirname $(find  /sys/bus/usb/devices/usb[1-5]/ -iname "*vendor*"|xargs grep $vendorid|cut -f1 -d: ))

# Verify it's the hdd
grep $productid $USBDIR/idProduct

#Power off 
if [ $? -eq 0 ]; then
sudo umount /mnt/audio/ && echo suspend |sudo tee $USBDIR/power/level;
fi
~/bin/poweron-usbdisk.sh

#!/bin/sh

# Poweron a device identified by the vendor/product id below.

# Look for western digital
USBDIR=$(dirname $(find  /sys/bus/usb/devices/usb[1-5]/ -iname "*vendor*"|xargs grep $vendorid |cut -f1 -d: ))
vendorid=1058
productid=0704


# Verify it's the hdd
grep $productid $USBDIR/idProduct

#Power off 
if [ $? -eq 0 ]; then  echo on |sudo tee $USBDIR/power/level; fi