[php] 獲取請求 IP 地址，及所處 IP 所在服務商代碼

// 獲取 IP 地址 
function get_remote_addr()
{
	if (isset($_SERVER["HTTP_X_REAL_IP"]))
	{
		return $_SERVER["HTTP_X_REAL_IP"];
	}
	else if (isset($_SERVER["HTTP_X_FORWARDED_FOR"]))
	{
		return preg_replace('/^.+,\s*/', '', $_SERVER["HTTP_X_FORWARDED_FOR"]);
	}
	else
	{
		return $_SERVER["REMOTE_ADDR"];
	}
}
// 根據 IP 地址，獲取 IP 所處運營商名稱
function get_ip_location_cn($ip)
{
	if (function_exists('curl_init'))
	{
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, "http://cn.ip.cn/?ip=" . $ip);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
		curl_setopt($ch, CURLOPT_USERAGENT, "curl/7.55.1");
		$result = curl_exec($ch);
		if (curl_getinfo($ch, CURLINFO_HTTP_CODE) != 200) {
			$result = '';
		}
		curl_close($ch);
	}
	else
	{
		$options = array('http'=>array('method'=>"GET", 'header'=>"User-Agent: curl/7.55.1\r\n"));
		$result = file_get_contents('http://cn.ip.cn/?ip=' . $ip, false, stream_context_create($options));
		if ($result === false) {
			$result = '';
		}
	}
	$location = trim(substr($result, strrpos($result, '：')+3));
	return substr($location, 0, 100);
}