A BASH function to wait for `apt` to finish and release all locks.

apt_wait.sh

#!/usr/bin/env bash

apt_wait () {
  while sudo fuser /var/lib/dpkg/lock >/dev/null 2>&1 ; do
    sleep 1
  done
  while sudo fuser /var/lib/apt/lists/lock >/dev/null 2>&1 ; do
    sleep 1
  done
  if [ -f /var/log/unattended-upgrades/unattended-upgrades.log ]; then
    while sudo fuser /var/log/unattended-upgrades/unattended-upgrades.log >/dev/null 2>&1 ; do
      sleep 1
    done
  fi
}