Remove expired kernel in Ubuntu

ubuntu-remove-expired-kernel.sh

#!/bin/bash

installed=( $(dpkg-query -W --showformat='${Package}\n' | grep -oP '^linux-image-\K\d.*' | sort -r) )
running=$(uname -r)

echo Installed versions: ${installed[@]}
if [[ ${#installed[@]} -le 1 ]]; then
	echo Nothing to do
	exit
fi

if [[ ${installed[0]} != $running ]]; then
	echo Must reboot system to load ${installed[0]}
	echo Current version $running
	exit
fi

packages=
for version in ${installed[@]}
do
	if [[ $version == ${installed[0]} ]]; then
		continue
	fi

	packages="linux-headers-${version} linux-image-${version} linux-modules-${version} linux-modules-extra-${version} $packages"
done

echo Packages to uninstall: $packages
apt autoremove --purge $packages