利用php怎么强制用户转向www域名？很多新手对此不是很清楚，为了帮助大家解决这个难题，下面小编将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。
// Install info.:
// Copy and paste these lines into your default index.php or
// the file that get's called if a visitor comes on your
// website...
// read the host from the server environment
$host = $_SERVER["HTTP_HOST"];
// fix host name - we never now... ;-)
$host = strtolower($host);
$host = trim($host);
// This is important:
// Webbrowsers like Firefox are doing their request without
// the port number like "www.jb51.net" but some other
// applications send host names like "www.jb51.net:80"
$host = str_replace(':80', '', $host);
$host = trim($host);
// if the host is not starting with www. redirect the
// user to the same URL but with www :-)
if ($host != 'www.jb51.net'){
// You an also change the "!=" to "==", if you want to force
// the user to use the domain name without the www.
// send status header, so that search engines or other services
// detect that this is a permanent redirect and not a temporary
header('HTTP/1.1 301 Moved Permanently');
// read the URL the user requested:
$url = isset($_SERVER["REQUEST_URI"]) ? $_SERVER["REQUEST_URI"] : '';
// redirect the user to the new destination:
header('Location: https://www.jb51.net' . $url);
// Convert "special" chars -- cause we never now... ;-)
$url = htmlspecialchars($url);
// "fallback" link, if the browser is not supporting header redirects
print 'Please click here';
// stop the script execution here
exit;
}
// If the domain is www.jb51.net then go on with your PHP code
// of with your website...
// BTW: You need to replace jb51.net trough your own domain :-D 看完上述内容是否对您有帮助呢？如果还想对相关知识有进一步的了解或阅读更多相关文章，请关注创新互联行业资讯频道，感谢您对创新互联网站建设公司，的支持。