PHP 实现获取服务器端IP地址

<?php
/**
* 获取服务器端IP地址
* @return string
*/
function get_server_ip() {
if (isset($_SERVER)) {
if($_SERVER['SERVER_ADDR']) {
$server_ip = $_SERVER['SERVER_ADDR'];
} else {
$server_ip = $_SERVER['LOCAL_ADDR'];
}
} else {
$server_ip = getenv('SERVER_ADDR');
}
return $server_ip;
}
echo "This Server IP is: ".get_server_ip();
?>