Michal Borychowski

I wanted to redirect users to the main page of the website according to his/her browser default language setting.

This setting is sent by the browser at every request to the server as ‘Accept-Language’ header and can look like this “pl,en-us;q=0.7,en;q=0.3″. You can check it with Live HTTP Headers Add-on for Firefox and read more about this header at W3C HTTP specification.

In PHP I could do it by checking the value of $_SERVER['HTTP_ACCEPT_LANGUAGE'] and issuing the header(”Location: /LANG/foo.php”,TRUE,301); command.

But I didn’t want to use PHP and did want to do it with .htaccess and mod rewrite. The first thought was to use RewriteCond %{HTTP_ACCEPT_LANGUAGE} as the analogy to RewriteCond %{HTTP_USER_AGENT} or RewriteCond %{HTTP_REFERER}. Unfortunately RewriteCond %{HTTP_ACCEPT_LANGUAGE} does not work! This variable is not present.

What is the solution? Looking more closely at the documentation at http://httpd.apache.org/docs/2.2/mod/mod_rewrite.html we have:

%{HTTP:header}, where header can be any HTTP MIME-header name, can always be used to obtain the value of a header sent in the HTTP request.

Which means we can obtain the value of default language setting of the browser by using RewriteCond %{HTTP:Accept-Language}. This is the simple solution, difficult to find on the web.

So if we have a website with three languages: English, German and Spanish and we want English to be the default we would use for example this in .htaccess:

#The 'Accept-Language' header starts with 'de'
#and the test is case-insensitive ([NC])
RewriteCond %{HTTP:Accept-Language} ^de [NC]
#Redirect user to /de/hauptseite address
#sending 301 (Moved Permanently) HTTP status code
RewriteRule ^$ /de/hauptseite [L,R=301]

RewriteCond %{HTTP:Accept-Language} ^es [NC]
RewriteRule ^$ /es/pagina-primera [L,R=301]

#For every other language (including English :)) use English
RewriteRule ^$ /en/main-page [L,R=301]

If you need to be more specific (eg. redirect accordingly to US or Great Britain English (en-us and en-gb)) you would not check only the first two signs of ‘Accept-Language’ header but you would need to prepare a little bit more complicated regular expression (some language settings are only two signs, some five signs).

I also thought about possibility of changing redirection addresses from within the CMS system (so that the admin can change main-page, hauptseite or pagina-primera to whatever he/she wishes). The best way would be to save this information in another file (e.g. lang-redirects.conf) and include it within .htaccess. Unfortunately config files inclusion is not possible in .htaccess scope. Another solution I thought about was using mapping-function but it doesn’t work, either.
So the only we can do is to edit .htaccess itself. If anyone knows a nicer solution  please share it with us.

Do you know any other tips & tricks regarding .htaccess and/or mod rewrite? We are waiting.