diff options
Diffstat (limited to 'scripts/setntpdate.sh')
| -rwxr-xr-x | scripts/setntpdate.sh | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/scripts/setntpdate.sh b/scripts/setntpdate.sh new file mode 100755 index 0000000..bf0a753 --- /dev/null +++ b/scripts/setntpdate.sh @@ -0,0 +1,49 @@ +#!/bin/sh + +resolve() { + local domain="$1" + local server="$2" + + if [ -x "$(command -v dig)" ]; then + if [ -z "$server" ]; then + dig +short "$domain" + else + dig +short "@$server" "$domain" + fi + return $? + fi + + if [ -x "$(command -v drill)" ]; then + if [ -z "$server" ]; then + drill "$domain" | grep "^${domain}." | cut -d$'\t' -f5 + else + drill "@$server" "$domain" | grep "^${domain}." |\ + cut -d$'\t' -f5 + fi + return $? + fi + exit 1 +} + +try_update() { + while read ip; do + if ntpdate -bu "$ip"; then + return 0 + fi + done + + return 1 +} + +pool="pool.ntp.org" +dns="1.1.1.1" + +# try default DNS server first +resolve "$pool" "" | try_update +[ $? -eq 0 ] && exit 0 + +# try fallback public dns server +ping -q -c 1 "$dns" || exit 1 + +resolve "$pool" "$dns" | try_update +exit $? |