ip2long()函数是PHP中的内置函数，可将IPv4地址(点分IP地址)转换为长整数。

用法:

int ip2long( string $ip_address )

参数：该函数接受上述和以下描述的单个参数：

$ip_address:这是必需的参数，用于指定IP地址。 返回值：如果成功，此函数返回一个长整数，如果失败，则返回FALSE。

注意：

此函数在PHP 4.0.0和更高版本上可用。 此函数适用于不完整的IP地址。 以下示例程序旨在说明PHP中的ip2long()函数：

实例1:

<?php 

// Store host name into variable 
$host="geeksforgeeks.org"; 

// Get IP address from hostname 
$ip = gethostbyname($host); 

echo "These three URLs are equivalent:<br>"; 

$out = "1. https://" . $host . "/<br>" .  
       "2. https://" . $ip . "/<br>" . 
       "3. https://" . sprintf("%u", ip2long($ip)) . "/"; 

echo $out; 

?>

输出：

These three URLs are equivalent:
1. https://geeksforgeeks.org/
2. https://52.25.109.230/
3. https://874081766/

实例2:

<?php 

// Store the list of hostname in an arry 
$hosts = array( 
    "geeksforgeeks.org", 
    "www.google.com",  
    "www.youtube.com", 
    "www.facebook.com", 
    "www.quora.com",  
    "www.stackoverflow.com"
); 

$out = "Equivalent Contents:";  

foreach( $hosts as $host ) { 

    $ip = gethostbyname($host); 

    $out .= "<br>https://" . $host . "/  https://" . $ip .  
            "/  https://" . sprintf("%u", ip2long($ip)) . "/"; 
} 

echo $out; 

?>

输出：

Equivalent Contents:
https://geeksforgeeks.org/ https://52.25.109.230/ https://874081766/
https://www.google.com/ https://172.217.167.196/ https://2899945412/
https://www.youtube.com/ https://172.217.18.206/ https://2899907278/
https://www.facebook.com/ https://185.60.216.35/ https://3107772451/
https://www.quora.com/ https://151.101.1.2/ https://2539979010/
https://www.stackoverflow.com/ https://151.101.1.69/ https://2539979077/