🛡️ Hosts 自动更新脚本

📜 脚本功能

自动更新系统 hosts 文件，有效防止 DNS 污染，支持：

• 自定义域名解析更新
• GitHub 专用 hosts 更新
• 自定义 IP 映射规则
• 多平台支持 (Linux/Synology)

⚙️ 配置说明

编辑脚本开头配置区域：

脚本功能

#!/bin/sh
# 自动更新 hosts 列表，支持自定义添加 host，有效防止 DNS 污染

### 配置区域 (按需修改) ###
CUSTOM_IP[1]='18.173.219.5 api.themoviedb.org'  # 自定义 IP 映射
DOMAIN_HOST=1  # 启用域名解析更新 (1=开启, 0=关闭)
GITHUB_HOST=1  # 启用 GitHub hosts 更新

### 域名列表 ###
DOMAIN_LIST=(
    api.themoviedb.org
    image.tmdb.org
    www.opensubtitles.org
    # 在此添加更多域名...
)

### 常量定义 ###
GITHUB_HOST_URL="https/hosts.gitcdn.top/hosts.txt"
DNS_API="https/networkcalc.com/api/dns/lookup"

### 执行逻辑 (无需修改) ###
REMOTE_GITHUB_HOST_AT=$(curl -s $GITHUB_HOST_URL | grep -w "# last fetch time:")
LOCAL_GITHUB_HOST_AT=$(grep -w "# last fetch time:" /etc/hosts)

check_domain_host() {
    # 检查域名解析函数
    for DOMAIN in "${DOMAIN_LIST[@]}"; do
        DOMAIN_IP_LIST=$(curl -sX GET "$DNS_API/$DOMAIN" | jq -r '.records.A[].address')
        [ -z "$DOMAIN_IP_LIST" ] && continue

        for DOMAIN_IP in $DOMAIN_IP_LIST; do
            if ! grep -q "$DOMAIN_IP" /etc/hosts; then
                sed -i "/# fetch-domain-hosts begin/Q" /etc/hosts
                break 2
            fi
        done
    done
}

write_domain_host() {
    # 写入域名解析函数
    if ! grep -q "fetch-domain-hosts" /etc/hosts; then
        echo -e "\n# fetch-domain-hosts begin" >> /etc/hosts
        for DOMAIN in "${DOMAIN_LIST[@]}"; do
            curl -sX GET "$DNS_API/$DOMAIN" | 
                jq -r '.records.A[].address + " " + "'"$DOMAIN"'"' >> /etc/hosts
        done
        echo "# fetch-domain-hosts end" >> /etc/hosts

        echo -e "\n# fetch-custom-hosts begin" >> /etc/hosts
        for ip_entry in "${CUSTOM_IP[@]}"; do
            echo "$ip_entry" >> /etc/hosts
        done
        echo "# fetch-custom-hosts end" >> /etc/hosts
    fi
}

### 主执行流程 ###
[ "$DOMAIN_HOST" = 1 ] && { check_domain_host; write_domain_host; }

if [ "$GITHUB_HOST" = 1 ] && [ -n "$REMOTE_GITHUB_HOST_AT" ]; then
    if ! grep -q "fetch-github-hosts" /etc/hosts; then
        curl -s "$GITHUB_HOST_URL" >> /etc/hosts
    elif [ "$REMOTE_GITHUB_HOST_AT" != "$LOCAL_GITHUB_HOST_AT" ]; then
        sed -i "/# fetch-github-hosts begin/Q" /etc/hosts
        curl -s "$GITHUB_HOST_URL" >> /etc/hosts
    fi
fi

### 输出结果 ###
cp /etc/hosts /volume2/RunSrcipt/hosts.txt