Purge old Ubuntu kernels

apt-purge-old-kernels

#!/bin/dash

SUFFIX=$(uname -r | sed "s/^\(.*\)-\([^0-9]\+\)$/\2/")
GENERIC_VERSION=$(dpkg -l linux-$SUFFIX | awk '/^ii/{print $3}' | sed 's#^\([0-9]\+\)\.\([0-9]\+\)\.\([0-9]\+\)\.\([0-9]\+\)\..*$#\1.\2.\3-\4#g' )
CURRENT_VERSION=$(uname -r | sed "s/^\(.*\)-\([^0-9]\+\)$/\1/")

dpkg -l 'linux-image-*' 'linux-headers-*' \
	| grep -v 'linux-image-'$SUFFIX | grep -v 'linux-headers-'$SUFFIX \
	| grep -v $GENERIC_VERSION | grep -v $CURRENT_VERSION \
	| awk '/^ii/{print $2}' \
	| xargs sudo apt-get -y purge