#!/bin/bash
# ============================================================
# DNS测速脚本（非浏览器版）- 由 W3CTool DNS测速工具生成
# 原理: 直接请求DoH服务器的JSON API接口，测量完整HTTP往返耗时,
#       该时间反映了到DNS服务器的网络延迟+服务器处理延迟
# 依赖: curl（任意版本）、awk
# 用法: bash dns-speed-test.sh [域名]
# 提示: 默认测量A记录(IPv4), 需测AAAA(IPv6)将脚本中type=1改为type=28
# ============================================================

DOMAIN="${1:-w3ctool.com}"

# DNS服务器列表（名称|JSON API地址），可自行增删
SERVERS=(
  "阿里DNS|https://dns.alidns.com/resolve"
  "DNSPod(腾讯)|https://doh.pub/resolve"
  "360安全DNS|https://doh.360.cn/resolve"
  "Google|https://dns.google/resolve"
  "Cloudflare|https://cloudflare-dns.com/resolve"
  "Quad9|https://cloudflare-dns.com/resolve"
  "OpenDNS|https://cloudflare-dns.com/resolve"
  "AdGuard|https://cloudflare-dns.com/resolve"
  "NextDNS|https://cloudflare-dns.com/resolve"
  "Mullvad|https://cloudflare-dns.com/resolve"
  "Wikimedia|https://cloudflare-dns.com/resolve"
  "Control D|https://cloudflare-dns.com/resolve"
  "CIRA加拿大|https://cloudflare-dns.com/resolve"
  "Restena卢森堡|https://cloudflare-dns.com/resolve"
  "SWITCH瑞士|https://cloudflare-dns.com/resolve"
)

echo "DNS测速: ${DOMAIN}   $(date "+%Y-%m-%d %H:%M:%S")"
echo "------------------------------------------------------------"
printf "%-24s %10s\n" "DNS服务器" "解析耗时"
echo "------------------------------------------------------------"

RANK=()
for item in "${SERVERS[@]}"; do
  name="${item%%|*}"
  api="${item##*|}"
  t=$(curl -s -o /dev/null --max-time 10 -H "accept: application/dns-json" -w "%{time_total}" "${api}?name=${DOMAIN}&type=1" 2>/dev/null)
  rc=$?
  if [ $rc -ne 0 ] || [ -z "$t" ] || [ "$t" = "000" ] || [ "$t" = "0.000000" ]; then
    printf "%-24s %10s\n" "$name" "失败"
    RANK+=("999999|${name}(失败)")
  else
    ms=$(awk -v t="$t" 'BEGIN{printf "%.0f", t*1000}')
    printf "%-24s %8s ms\n" "$name" "$ms"
    RANK+=("${ms}|${name}")
  fi
done

echo "------------------------------------------------------------"
BEST=$(printf "%s\n" "${RANK[@]}" | sort -t"|" -k1 -n | head -1 | cut -d"|" -f2)
echo "⚡ 推荐DNS: ${BEST}"

提示：脚本内置全部DNS服务商列表（可直接编辑增删），域名与记录类型默认取自当前输入，也可通过命令行参数覆盖，如 python dns-speed-test.py qq.com AAAA。