上周去迅雷面试，郁闷死了，题好难，这题不会，大家帮看看。

[wurunduo]

www.xunlei.com被解析到10个ip,现要监控http://www.xunlei.com/index.html 比较10个点的index.html内容是否相同，写出详细思路

[wurunduo]

忘了写备注了：（不允许通过ip访问）

[qq120848369]

C语言的话：getaddrinfo拿到所有10个IP，顺序connnect,request,response得到10个index.html, 每个文件做md5，比较10个md5是否相同即可。

用Php写此功能，10行代码都嫌多。
shell写此功能，10行代码差不多。

[qq120848369]

[User:root Time:20:03:55 Path:/home/liangdong/c]$ nslookup www.xunlei.com
Server:         10.65.1.1
Address:        10.65.1.1#53

Non-authoritative answer:
www.xunlei.com  canonical name = www.co.sandai.net.
Name:   www.co.sandai.net
Address: 121.14.82.141
Name:   www.co.sandai.net
Address: 121.14.82.142
Name:   www.co.sandai.net
Address: 119.147.41.48
Name:   www.co.sandai.net
Address: 119.147.41.83
Name:   www.co.sandai.net
Address: 121.14.82.140

[User:root Time:20:04:00 Path:/home/liangdong/c]$ cat src/main.c 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>

int main(int argc, char* const argv[]) {
        struct addrinfo *res;
        struct addrinfo hint;

        memset(&hint, 0, sizeof(hint));
        hint.ai_socktype = SOCK_STREAM;
        hint.ai_flags = AI_ADDRCONFIG;

        if (0 != getaddrinfo("www.xunlei.com", NULL, &hint, &res)) {
                perror("getaddrinfo => ");
                return -1;
        }

        char ip_str[50];
        sa_family_t family;
        struct sockaddr_in *ipv4_addr;
        struct sockaddr_in6 *ipv6_addr;
        const void *ip_addr = NULL;

        for ( ; res != NULL; res = res->ai_next) {
                family = res->ai_family;
                switch (family) {
                        case AF_INET:
                                ipv4_addr = (struct sockaddr_in*)res->ai_addr;
                                ip_addr = (const void*)&(ipv4_addr->sin_addr);
                                break;
                        case AF_INET6:
                                ipv6_addr = (struct sockaddr_in6*)res->ai_addr;
                                ip_addr = (const void*)&(ipv6_addr->sin6_addr);
                                break;
                        default:
                                break;
                }
                const char *ret = inet_ntop(res->ai_family, ip_addr, ip_str, (socklen_t)sizeof(ip_str));
                if (ret != NULL) {
                        printf("%s\n", ret);
                }
        }

        return 0;
}

以上是C和SHELL获取DNS的方法，剩下的就是C里做TCP连接请求与应答，SHELL里用curl即可，注意xunlei要求Host：必须是www.xunlei.com, 否则将拒绝服务。

下面是php的代码，因为简单所以写了一下：

[User:root Time:20:35:43 Path:/home/liangdong/php]$ php xunlei.php 
358cc42d2669f32e361de6a185a312aa
358cc42d2669f32e361de6a185a312aa
358cc42d2669f32e361de6a185a312aa
358cc42d2669f32e361de6a185a312aa
358cc42d2669f32e361de6a185a312aa
all the same
[User:root Time:20:35:54 Path:/home/liangdong/php]$ cat xunlei.php 
<?php
$ips = dns_get_record("www.xunlei.com", DNS_A);
$md5s = array();

foreach ($ips as $rec) {
        $ip = $rec['ip'];
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_URL, $ip);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_HTTPHEADER, array("Host: www.xunlei.com"));
        curl_setopt($curl, CURLOPT_TIMEOUT, 2);
        while (($page = curl_exec($curl)) === false) {
                sleep(1);
        }
        $md5 = md5($page);
        $md5s[] = $md5;
        echo $md5 . PHP_EOL;
}

$result = array_unique($md5s);
if (count($result) == 1) {
        echo "all the same" . PHP_EOL;
}
?>

[ImFantasy]

[Quote=引用 3 楼 的回复:]

C/C++ code
[User:root Time:20:03:55 Path:/home/liangdong/c]$ nslookup www.xunlei.com
Server: 10.65.1.1
Address: 10.65.1.1#53

Non-authoritative answer:
www.xunlei.com canonical name ……
[/Quote]
学习了。

[xjpphp]

[Quote=引用 3 楼 的回复:]

C/C++ code
[User:root Time:20:03:55 Path:/home/liangdong/c]$ nslookup www.xunlei.com
Server: 10.65.1.1
Address: 10.65.1.1#53

Non-authoritative answer:
www.xunlei.com canonical name ……
[/Quote]

膜拜！！！