从file_get_contents请求中获取IP

$postdata = http_build_query( array(\'install\' => \'true\', \'url\' => $_SERVER[\'SERVER_NAME\'], \'key\' => \'XXXXXXXXXXXX\') );

$opts = array(\'http\' =>
    array(
        \'method\'  => \'POST\',
        \'header\'  => \'Content-type: application/x-www-form-urlencoded\',
        \'content\' => $postdata
    )
);

$context  = stream_context_create($opts);
$registration_key = file_get_contents(\'http://example.com/register.php\', false, $context);

$_SERVER[\'HTTP_CLIENT_IP\']

$_SERVER[\'HTTP_VIA\']

$_SERVER[\'HTTP_X_FORWARDED_FOR\']

$_SERVER[\'REMOTE_ADDR\']