i3 filesaver script used with xautolock and bluetooth proximity

fuzzylock.sh

#!/bin/sh -e
DEVICE=E4:F8:EF:1F:D1:F4
DEV_NAME="K"

opt=`hcitool name $DEVICE`

if [ "$opt" = "$DEV_NAME" ]; then
    echo "Device '$opt' found"
else
    echo "Can't find device $DEVICE ($DEV_NAME); locking!"
    # Take a screenshot
    scrot -z /tmp/screen_locked.png

    # Pixellate it 10x
    mogrify -scale 10% -scale 1000% /tmp/screen_locked.png

    # Lock screen displaying this image.
    i3lock -i /tmp/screen_locked.png
fi