Php obtains the summary of root domain names, and php obtains the summary of domain names.

Php obtains the summary of root domain names, and php obtains the summary of domain names.

The examples in this article summarize how php obtains the root domain name and share it with you for your reference. The specific implementation method is as follows:

If you only get the domain name currently accessing your page, you only need to use the HTTP_HOST function in php. If you want to extract the url root domain name, you need regular expressions, let's take a look at several specific instances.

It is very easy to obtain the current domain name:

Copy codeThe Code is as follows: <? Php
// Obtain the current domain name:
Echo $ _ SERVER ['server _ name'];
// Obtain the source URL, that is, click the previous URL on this page.
Echo $ _ SERVER ["HTTP_REFERER"];
$ _ SERVER ['request _ URI ']; // obtain the suffix of the current domain name
$ _ SERVER ['HTTP _ host']; // obtain the current domain name
Dirname (_ FILE _); // obtain the physical path of the current FILE
Dirname (_ FILE _). "/../"; // obtain the upper-level physical path of the current FILE
?>

Example 1

Copy codeThe Code is as follows: function getUrlRoot ($ url ){
# Add the header and tail
$ Url = $ url ."/";
# Determining domain names
Preg_match ("/(\ w *):\/\/)? \ W *\.? ([\ W |-] * \. (com.cn | net.cn | gov.cn | org.cn | com | net | cn | org | asia | tel | mobi | me | TV | biz | cc | name | info ))
\\// ", $ Url, $ ohurl );
# Determining IP addresses
If ($ ohurl [3] = ''){
Preg_match ("/(\ d + \.) {3} \ d +) \ //", $ url, $ ohip );
Return $ ohip [1];
}
Return $ ohurl [3];
}

Example 2

Copy codeThe Code is as follows :/**
* Get the root domain name
* @ Param type $ domain Name
* @ Return string returns the root domain name.
*/
Function GetUrlToDomain ($ domain ){
$ Re_domain = '';
$ Domain_postfix_cn_array = array ("com", "net", "org", "gov", "edu", "com.cn", "cn ");
$ Array_domain = explode (".", $ domain );
$ Array_num = count ($ array_domain)-1;
If ($ array_domain [$ array_num] = 'cn '){
If (in_array ($ array_domain [$ array_num-1], $ domain_postfix_cn_array )){
$ Re_domain = $ array_domain [$ array_num-2]. ".". $ array_domain [$ array_num-1]. ".". $ array_domain [$ array_num];
} Else {
$ Re_domain = $ array_domain [$ array_num-1]. ".". $ array_domain [$ array_num];
}
} Else {
$ Re_domain = $ array_domain [$ array_num-1]. ".". $ array_domain [$ array_num];
}
Return $ re_domain;
}

I hope this article will help you with php programming.

How to extract the regular expression of the root domain name from a php segment

([0-9a-zA-Z-.] +? \.)? [0-9a-zA-Z-] \. [a-zA-Z] {2, 4} $
 
How can I use php to obtain the IP address corresponding to the domain name?

Gethostbyname (PHP 3, PHP 4, PHP 5)

Gethostbyname -- get the IP address of the specified Machine name

Function Format description:
String gethostbyname (string hostname)

Returns the IP address of the hostname.

Example 1. A simple gethostbyname () example

<? Php
$ Ip = gethostbyname ('www .example.com ');

Echo $ ip;
?>