PHP获取主机名、域名函数

说明
array gethostbynamel ( string $hostname )
Returns a list of IPv4 addresses to which the Internet host specified by hostname resolves. 

参数
hostname The host name. 

返回值
Returns an array of IPv4 addresses or FALSE if hostname could not be resolved. 

gethostbyname — Get the IPv4 address corresponding to a given Internet host name 

说明
string gethostbyname ( string $hostname )
Returns the IPv4 address of the Internet host specified by hostname. 

参数
hostname The host name. 

返回值
Returns the IPv4 address or a string containing the unmodified hostname on failure. 

gethostbyaddr — Get the Internet host name corresponding to a given IP address 

说明
string gethostbyaddr ( string $ip_address )
Returns the host name of the Internet host specified by ip_address. 

参数
ip_address 
The host IP address. 

返回值
Returns the host name on success, the unmodified ip_address on failure, or FALSE on malformed input. 

<span>$hostname</span> = 'www.baidu.com'<span>;
</span><span>$addr</span> = '127.0.0.1'<span>;

</span><span>print_r</span>(<span>gethostbyname</span>(<span>$hostname</span><span>));
</span><span>echo</span> '<br>'<span>;

</span><span>print_r</span>(<span>gethostbyaddr</span>(<span>$addr</span><span>));
</span><span>echo</span> '<br>'<span>;

</span><span>print_r</span>(<span>gethostbynamel</span>(<span>$hostname</span>));

220.181.111.148
idc-wang
Array ( [0] => 220.181.111.148 [1] => 220.181.112.143 )