bash script to unlock, mount, backup to, unmount, and lock an encrypted external drive

encmount.sh

#! /bin/bash
backupfrom="/srv/smb/"
blockdev=${1:-/dev/sdd1}

permunlock=$(pkaction|grep org.freedesktop.udisks2.encrypted-unlock)
permmount=$(pkaction|grep org.freedesktop.udisks2.filesystem-mount)

if [[ -z "$permunlock" ]] || [[ -z "$permmount" ]]; then
    echo "enter disk password first, then login password twice"
    echo "login password prompts can be eliminated via polkit"
    echo "see script source for details"
fi

device=$(udisksctl unlock -b $blockdev | grep -Po "(?<= as )/[0-9A-Za-z/-]+")
direct=$(udisksctl mount -b $device | grep -Po "(?<= at )/[0-9A-Za-z/-]+")
if [[ $? -eq 0 ]] ; then
    rsync -atP --del $backupfrom $direct
fi
udisksctl unmount -b $device
udisksctl lock -b $blockdev

exit

# add polkit permissions in /etc/polkit-1/localauthority/50-local.d/10-encmount.pkla
# I'm not sure what all of these do
[udisks]
Identity=unix-group:sudo
Action=org.freedesktop.udisks2.*
ResultAny=yes
ResultInactive=no
ResultActive=yes