重定向到網站如果www部分丟失使用PHP

Question

我問了同樣的問題Redirect to site if WWW part is missing但我的情況沒有幫助，因爲我無法改變CNAME和.htaccess也失敗了。
剩下的唯一選擇是使用PHP。
任何人都可以幫助我嗎？

如果有人試圖瀏覽example.com或example.com/左右PHP將重定向它www.example.com/ ..

edit

SetEnv TZ Asia/Calcutta 

ErrorDocument 400 /error.html 
ErrorDocument 401 /error.html 
ErrorDocument 403 /error.html 
ErrorDocument 404 /error.html 

<ifModule mod_php4.c> 
php_value zlib.output_compression 16386 
</ifModule> 

<IfModule mod_rewrite.c> 
RewriteEngine on 
RewriteBase/

RewriteRule ^home$ home.php [L] 

RewriteRule ^credit$ credits.php [L] 
RewriteRule ^credits$ credits.php [L] 

RewriteRule ^profile/(\d+)/?$ profile.php?id=$1 [L] 
RewriteRule ^user/(\d+)/?$ view_profile.php?id=$1 [L] 

RewriteRule ^blog/?$ blog.php [L] 
RewriteRule ^blog/(\d+)/?$ blog.php?id=$1 [L] 
RewriteRule ^blog.php/(\d+)/?$ blog.php?id=$1 [L] 
RewriteRule ^blog/(\d+)/([A-Za-z0-9-_\[\]]+)/?$ blog.php?id=$1&title=$2 [L] 
RewriteRule ^blog.php/(\d+)/([A-Za-z0-9-_\[\]]+)/?$ blog.php?id=$1&title=$2 [L] 

RewriteRule ^blogbyauthor.php/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 
RewriteRule ^blogbyauthor/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 
RewriteRule ^blogbyauthor/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 

RewriteRule ^blog_by_category.php/([A-Za-z0-9-_\[\]]+)/?$ blog_by_category.php?category=$1 [L] 
RewriteRule ^blog_by_category/([A-Za-z0-9-_\[\]]+)/?$ blog_by_category.php?category=$1 [L] 
</IfModule> 

Answer 1

試試這個在.htaccess中：

<IfModule mod_rewrite.c> 
    Options +FollowSymlinks 
    RewriteEngine on 

    # site.com -> www.site.com 
    RewriteCond %{HTTP_HOST} ^site.com 
    RewriteRule ^(.*)$ http://www.site.com/$1 [R=301,L] 

</IfModule> 

顯然你應該更換site.com與您的域名。

---

更新：結合你的代碼我的建議。

SetEnv TZ Asia/Calcutta 

ErrorDocument 400 /error.html 
ErrorDocument 401 /error.html 
ErrorDocument 403 /error.html 
ErrorDocument 404 /error.html 

<ifModule mod_php4.c> 
php_value zlib.output_compression 16386 
</ifModule> 

<IfModule mod_rewrite.c> 
RewriteEngine on 
RewriteBase/

# site.com -> www.site.com 
RewriteCond %{HTTP_HOST} ^site.com 
RewriteRule ^(.*)$ http://www.site.com/$1 [R=301,L] 

RewriteRule ^home$ home.php [L] 

RewriteRule ^credit$ credits.php [L] 
RewriteRule ^credits$ credits.php [L] 

RewriteRule ^profile/(\d+)/?$ profile.php?id=$1 [L] 
RewriteRule ^user/(\d+)/?$ view_profile.php?id=$1 [L] 

RewriteRule ^blog/?$ blog.php [L] 
RewriteRule ^blog/(\d+)/?$ blog.php?id=$1 [L] 
RewriteRule ^blog.php/(\d+)/?$ blog.php?id=$1 [L] 
RewriteRule ^blog/(\d+)/([A-Za-z0-9-_\[\]]+)/?$ blog.php?id=$1&title=$2 [L] 
RewriteRule ^blog.php/(\d+)/([A-Za-z0-9-_\[\]]+)/?$ blog.php?id=$1&title=$2 [L] 

RewriteRule ^blogbyauthor.php/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 
RewriteRule ^blogbyauthor/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 
RewriteRule ^blogbyauthor/(\d+)/?$ blogbyauthor.php?uid=$1 [L] 

RewriteRule ^blog_by_category.php/([A-Za-z0-9-_\[\]]+)/?$ blog_by_category.php?category=$1 [L] 
RewriteRule ^blog_by_category/([A-Za-z0-9-_\[\]]+)/?$ blog_by_category.php?category=$1 [L] 
</IfModule> 

Answer 2

$protocol = (@$_SERVER["HTTPS"] == "on") ? "https://" : "http://"; 

if (substr($_SERVER['HTTP_HOST'], 0, 4) !== 'www.') { 
    header('Location: '.$protocol.'www.'.$_SERVER['HTTP_HOST'].'/'.$_SERVER['REQUEST_URI']); 
    exit; 
} 

Answer 3

另一個（非常相似，起源）PHP解決方案..

$s = empty($_SERVER["HTTPS"]) ? '' : ($_SERVER["HTTPS"] == "on") ? "s" : ""; 
$protocol = substr(strtolower($_SERVER["SERVER_PROTOCOL"]), 0, strpos($_SERVER["SERVER_PROTOCOL"], "/")).$s.'://'; 
$domain = $_SERVER['SERVER_NAME']; 

$mypath = $protocol.$domain; 

if($mypath == 'http://yourdomain.com') { 
    $uri = ''; 
    if(isset($_SERVER['REQUEST_URI'])) { 
     $uri = $_SERVER['REQUEST_URI'];   
    } 
    header ('HTTP/1.1 301 Moved Permanently'); 
    header ('Location: http://www.yourdomain.com'.$uri); 
    exit; 
} 

我希望這有助於。