/etc/network/if-down.d/resolvconf is in resolvconf 1.79.
This file is owned by root:root, with mode 0o755.
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 | #!/bin/sh
#
# ifdown hook script for resolvconf
#
# This file is part of the resolvconf package.
#
[ -x /sbin/resolvconf ] || exit 0
case "$ADDRFAM" in
inet|inet6) : ;;
*) exit 0 ;;
esac
/sbin/resolvconf -d "${IFACE}.${ADDRFAM}" || :
|