How to query domain name information from whois server using PHP

[Foreword]

In the world of the Internet, a domain name is the portal through which a website enters. It is the link address we enter when visiting a website. It is also an important item that we need to purchase and configure when creating a website.

For website administrators and network security engineers, it is also necessary to understand the relevant information of the domain name, such as: domain name owner, registration information, DNS, etc.

Today we will introduce how to use PHP to query domain name information from the whois server.

[Preparation]

Before conducting the query, we need to first understand the whois service.

Whois refers to a query protocol that provides domain name information query services on the Internet. We can query the information of a domain name through whois, including the registrant, registration time, expiration time, DNS server information, etc.

At the same time, we also need to prepare some basic knowledge: HTTP protocol and PHP network requests.

The HTTP protocol is a communication rule used to transmit hypertext between a web browser and a web server, while PHP's network requests are completed through curl or fsockopen.

Next, we use PHP code to implement the function of querying domain name information.

[PHP code for querying domain name information]

First, we need to create a form to allow users to enter the domain name they need to query in the input box, as shown below:

nbsp;html>


    <meta>
    <title>查询域名信息</title>


    

        

            

请输入要查询的域名：

                                  

    

Next, we need to write PHP code to perform the query function.

<?php if ($_SERVER[&#39;REQUEST_METHOD&#39;] == &#39;POST&#39;) {
    // 获取用户输入的域名
    $domain = $_POST[&#39;domain&#39;];

    // 查询域名信息
    $whois = get_whois($domain);

    // 输出查询结果
    echo "<pre class="brush:php;toolbar:false">";
    echo $whois;
    echo "

"; } // 获取域名信息 function get_whois($domain) {     // 指定whois服务器地址     $whois_server = "whois.domain.com";     // 连接whois服务器     $fp = fsockopen($whois_server, 43);     // 查询域名信息     fputs($fp, $domain . "\r\n");     // 获取查询结果     $whois = "";     while (!feof($fp)) {         $whois .= fgets($fp, 128);     }     fclose($fp);     // 返回查询结果     return $whois; } ?>

First, we determine whether the user has submitted a query request by checking the HTTP request method.

Next, we obtain the domain name entered by the user through $_POST and pass it to the get_whois function to obtain the whois information of the domain name.

In the get_whois function, we first specify the whois server address to query.

Next, connect to the whois server through the fsockopen function, use the fputs function to send a query request to the server, and obtain the query results through a while loop.

Finally, we return the query results and output the query results on the page.

[Summary]

Querying domain name information with PHP is very simple. You only need to use the fsockopen function to connect to the whois server and send a query request to the server.

Whether you are a website manager or a network security engineer, understanding domain name information is very helpful. Through the whois query protocol, we can obtain the registration information, owner, expiration time, DNS server information, etc. of the domain name.

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