ref: cbd0ebcb94afab9f5183ffc7e5a3ab1ed78d83d4
dir: /sys/lib/dist/ndb/mkfile/
dnsroot:V:
hget https://www.internic.net/domain/root.zone | awk '
BEGIN { print "# this file is autogenerated from /sys/lib/dist/ndb/mkfile" };
match($1, "\\.root-servers\\.net\\.") != 0 && \
($4 == "A" || $4 == "AAAA") {
dom = toupper($1);
sub("\\.$", "", dom);
printf("dom=%s ip=%s\n", dom, $5);
}' > $target