preinst is in libvirt-bin 0.9.8-2ubuntu17.23.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 | #!/bin/sh
set -e
case "${1}" in
	upgrade)
		# If the default network autostart symlink existed, then note
		# that here so we can recreate it at postinst.
		EXISTED="/etc/libvirt/qemu/networks/autostart/TMP_defaultexisted"
		if [ -e /etc/libvirt/qemu/networks/autostart/default.xml ]; then
			touch "$EXISTED"
		fi
		;;
	install|abort-upgrade)
			;;
	*)
		echo "preinst called with unknown argument \`${1}'" >&2
		exit 1
		;;
esac
# Automatically added by dh_installudev
if [ "$1" = install ] || [ "$1" = upgrade ]; then
	if [ -e "/etc/udev/rules.d/z60_libvirt-bin.rules" ]; then
		if [ "`md5sum \"/etc/udev/rules.d/z60_libvirt-bin.rules\" | sed -e \"s/ .*//\"`" = \
		     "`dpkg-query -W -f='${Conffiles}' libvirt-bin | sed -n -e \"\\\\' /etc/udev/rules.d/z60_libvirt-bin.rules '{s/ obsolete$//;s/.* //p}\"`" ]
		then
			rm -f "/etc/udev/rules.d/z60_libvirt-bin.rules"
		fi
	fi
fi
# End automatically added section
exit 0
 |