| @@ -0,0 +1,78 @@ | |||
| 1 | + | #!/bin/bash | |
| 2 | + | ||
| 3 | + | set -e | |
| 4 | + | ||
| 5 | + | URL="http://www.baidu.com/" | |
| 6 | + | COUNT=10 | |
| 7 | + | ||
| 8 | + | echo "正在通过百度 HTTP 校准系统时间..." | |
| 9 | + | echo | |
| 10 | + | ||
| 11 | + | best_rtt=999999999 | |
| 12 | + | best_time=0 | |
| 13 | + | ||
| 14 | + | for i in $(seq 1 "$COUNT"); do | |
| 15 | + | start=$(date +%s%3N) | |
| 16 | + | ||
| 17 | + | headers=$(curl \ | |
| 18 | + | --noproxy '*' \ | |
| 19 | + | --connect-timeout 3 \ | |
| 20 | + | --max-time 5 \ | |
| 21 | + | -sS \ | |
| 22 | + | -D - \ | |
| 23 | + | -o /dev/null \ | |
| 24 | + | "$URL" 2>/dev/null) || { | |
| 25 | + | echo "[$i/$COUNT] 请求失败" | |
| 26 | + | continue | |
| 27 | + | } | |
| 28 | + | ||
| 29 | + | end=$(date +%s%3N) | |
| 30 | + | ||
| 31 | + | date_header=$(printf '%s\n' "$headers" | | |
| 32 | + | grep -i '^Date:' | | |
| 33 | + | tail -n 1 | | |
| 34 | + | sed 's/^[Dd]ate:[[:space:]]*//') | |
| 35 | + | ||
| 36 | + | if [ -z "$date_header" ]; then | |
| 37 | + | echo "[$i/$COUNT] 未找到 Date 头" | |
| 38 | + | continue | |
| 39 | + | fi | |
| 40 | + | ||
| 41 | + | server_sec=$(date -u -d "$date_header" +%s 2>/dev/null) || { | |
| 42 | + | echo "[$i/$COUNT] 无法解析 Date: $date_header" | |
| 43 | + | continue | |
| 44 | + | } | |
| 45 | + | ||
| 46 | + | rtt=$((end - start)) | |
| 47 | + | half_rtt=$((rtt / 2)) | |
| 48 | + | ||
| 49 | + | # Date 头的时间 + 请求往返时间的一半 | |
| 50 | + | estimated_ms=$((server_sec * 1000 + half_rtt)) | |
| 51 | + | ||
| 52 | + | echo "[$i/$COUNT] RTT=${rtt}ms Date=$date_header" | |
| 53 | + | ||
| 54 | + | if [ "$rtt" -lt "$best_rtt" ]; then | |
| 55 | + | best_rtt=$rtt | |
| 56 | + | best_time=$estimated_ms | |
| 57 | + | fi | |
| 58 | + | done | |
| 59 | + | ||
| 60 | + | if [ "$best_time" -eq 0 ]; then | |
| 61 | + | echo | |
| 62 | + | echo "错误：无法从百度获取时间" | |
| 63 | + | exit 1 | |
| 64 | + | fi | |
| 65 | + | ||
| 66 | + | echo | |
| 67 | + | echo "最佳 RTT: ${best_rtt}ms" | |
| 68 | + | ||
| 69 | + | before=$(date '+%Y-%m-%d %H:%M:%S.%3N') | |
| 70 | + | ||
| 71 | + | # 设置系统时间 | |
| 72 | + | date -u -s "@$(awk "BEGIN {printf \"%.3f\", $best_time / 1000}")" >/dev/null | |
| 73 | + | ||
| 74 | + | after=$(date '+%Y-%m-%d %H:%M:%S.%3N') | |
| 75 | + | ||
| 76 | + | echo "校时前: $before" | |
| 77 | + | echo "校时后: $after" | |
| 78 | + | echo "校时完成。" | |
LiuShen / 通过HTTP同步时间
Last active 6 hours ago
在123端口无法使用的情况下通过http请求头携带的时间实现时间同步