Summary of PHP methods for obtaining domain names

This article mainly introduces PHP methods for obtaining domain names. examples summarize common methods for obtaining domain names, which are very useful, for more information about how to obtain a domain name in PHP, see the examples in this article. Share it with you for your reference. The specific implementation method is as follows:

Method 1 (using system variables)

The code is as follows:

// Disadvantage: Do not use the passed address or host that does not support system variables
Echo $ _ SERVER ['http _ host'];

　　　

Method 2 (using built-in functions)

The code is as follows:

$ Url = 'http: // www.jb51.net/index.php? Referer = jb51.net ';
$ Arr_url = parse_url ($ url );
Echo $ arr_url ['host'];

Method 3 (write functions by yourself)

The code is as follows:

Function getdomain ($ url)
{
$ Url = str_replace ('http: // ', ", $ url); // remove the http prefix
$ Pos = strpos ($ url ,'/');
If ($ pos = false)
{
Return $ url;
} Else
{
Return substr ($ url, 0, $ pos );
}
}
Echo getdomain ($ url );

Method 4 (using regular expressions)

The code is as follows:

Preg_match ("/^ (http ://)? ([^/] +)/I ", $ url, $ arr_domain );
Echo $ arr_domain [2];

I hope this article will help you with PHP programming.