Redirect non-www to www on magento

I am using Magento 1.9.1. This is my .htaccess code. ``` ############################################ ## uncomment these lines for CGI mode ## make sure to specify the correct cgi php binary file name ## it might be /cgi-bin/php-cgi # Action php5-cgi /cgi-bin/php5-cgi # AddHandler php5-cgi .php ############################################ ## GoDaddy specific options # Options -MultiViews ## you might also need to add this line to php.ini ## cgi.fix_pathinfo = 1 ## if it still doesn't work, rename php.ini to php5.ini ############################################ ## this line is specific for 1and1 hosting #AddType x-mapp-php5 .php #AddHandler x-mapp-php5 .php ############################################ ## default index file DirectoryIndex index.php <IfModule mod_php5.c> ############################################ ## adjust memory limit php_value memory_limit 512M php_value max_execution_time 18000 ############################################ ## disable magic quotes for php request vars php_flag magic_quotes_gpc off ############################################ ## disable automatic session start ## before autoload was initialized php_flag session.auto_start off ############################################ ## enable resulting html compression #php_flag zlib.output_compression on ########################################### # disable user agent verification to not break multiple image upload php_flag suhosin.session.cryptua off ########################################### # turn off compatibility with PHP4 when dealing with objects php_flag zend.ze1_compatibility_mode Off </IfModule> <IfModule mod_security.c> ########################################### # disable POST processing to not break multiple image upload SecFilterEngine Off SecFilterScanPOST Off </IfModule> <IfModule mod_deflate.c> ############################################ ## enable apache served files compression ## http://developer.yahoo.com/performance/rules.html#gzip # Insert filter on all content SetOutputFilter DEFLATE # Insert filter on selected content types only AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css text/javascript # Netscape 4.x has some problems... BrowserMatch ^Mozilla/4 gzip-only-text/html # Netscape 4.06-4.08 have some more problems BrowserMatch ^Mozilla/4\.0[678] no-gzip # MSIE masquerades as Netscape, but it is fine BrowserMatch \bMSIE !no-gzip !gzip-only-text/html # Don't compress images SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary # Make sure proxies don't deliver the wrong content Header append Vary User-Agent env=!dont-vary </IfModule> <IfModule mod_ssl.c> ############################################ ## make HTTPS env vars available for CGI mode SSLOptions StdEnvVars </IfModule> <IfModule mod_rewrite.c> ############################################ ## enable rewrites Options +FollowSymLinks RewriteEngine on ############################################ ## you can put here your magento root folder ## path relative to web root RewriteBase /shop/ ############################################ ## uncomment next line to enable light API calls processing # RewriteRule ^api/([a-z][0-9a-z_]+)/?$ api.php?type=$1 [QSA,L] ############################################ ## rewrite API2 calls to api.php (by now it is REST only) RewriteRule ^api/rest api.php?type=rest [QSA,L] ############################################ ## workaround for HTTP authorization ## in CGI environment RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}] ############################################ ## TRACE and TRACK HTTP methods disabled to prevent XSS attacks RewriteCond %{REQUEST_METHOD} ^TRAC[EK] RewriteRule .* - [L,R=405] ############################################ ## redirect for mobile user agents #RewriteCond %{REQUEST_URI} !^/mobiledirectoryhere/.*$ #RewriteCond %{HTTP_USER_AGENT} "android|blackberry|ipad|iphone|ipod|iemobile|opera mobile|palmos|webos|googlebot-mobile" [NC] #RewriteRule ^(.*)$ /mobiledirectoryhere/ [L,R=302] ############################################ ## always send 404 on missing files in these folders RewriteCond %{REQUEST_URI} !^/(media|skin|js)/ ############################################ ## never rewrite for existing files, directories and links RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteCond %{REQUEST_FILENAME} !-l ############################################ ## rewrite everything else to index.php RewriteRule .* index.php [L] </IfModule> ############################################ ## Prevent character encoding issues from server overrides ## If you still have problems, use the second line instead AddDefaultCharset Off #AddDefaultCharset UTF-8 <IfModule mod_expires.c> ############################################ ## Add default Expires header ## http://developer.yahoo.com/performance/rules.html#expires ExpiresDefault "access plus 1 year" </IfModule> ############################################ ## By default allow all access Order allow,deny Allow from all ########################################### ## Deny access to release notes to prevent disclosure of the installed Magento version <Files RELEASE_NOTES.txt> order allow,deny deny from all </Files> ############################################ ## If running in cluster environment, uncomment this ## http://developer.yahoo.com/performance/rules.html#etags FileETag none AddHandler application/x-httpd-php54 .php .php5 .php4 .php3 ``` The problem is that all pages on shop redirects to shop homepage instead of the `www`. version So for example now: http://mysite.ext/shop/category/ redirects to http://www.mysite.ext/shop/. It should just redirect to `www` version.