.htacces replace all underscores with hyphens

Question

I am having a struggle trying to get my .htaccess to remove all underscores from an url. I have a lot of old aliases in my articles and they are all with underscores. I have searched for a sollution, but couldnt find any.

example:

http://mysite.com/nl/nieuws/artikel/Article_name_underscores/999

http://mysite.com/nl/nieuws/artikel/article_name_with_underscores/999

http://mysite.com/nl/nieuws/artikel/article_name_with_More_underscores/999

What I am trying to get:

http://mysite.com/nieuws/article-name-with-underscore

http://mysite.com/nieuws/article-name-with-more-underscore

http://mysite.com/nieuws/article-name-with-even-more-underscore

As you can see I need to replace the underscore with hyphens and get it into lowercase, but the aliases are between 1 and 14 underscores. Now I've created the following rewrite rules:

RewriteRule ^nieuws/artikel/([^_]*)_([^_]*)_([^_]*)/([^_]*)$ http://mysite.com/nieuws/${lc:$1}-${lc:$2}-${lc:$3} [R=301,L]
RewriteRule ^nieuws/artikel/([^_]*)_([^_]*)_([^_]*)_([^_]*)/([^_]*)$ http://mysite.com/nieuws/${lc:$1}-${lc:$2}-${lc:$3}-${lc:$4} [R=301,L]
RewriteRule ^nieuws/artikel/([^_]*)_([^_]*)_([^_]*)_([^_]*)_([^_]*)/([^_]*)$ http://mysite.com/nieuws/${lc:$1}-${lc:$2}-${lc:$3}-${lc:$4}-${lc:$5} [R=301,L]

With the RewriteMap on the virtualhost ofcourse

RewriteMap lc int:tolower 

My question is, how do I get this dynamicly with efficient code to catch all alias between unlimited amounts of underscores?

Answer 1

This isn't the cleanest way, but it works. Because of the [L] in it for Last rule, it won't be a redirect loop because it exits once applied:

# Four underscores
RewriteCond %{REQUEST_URI} (.*)_(.*)_(.*)_(.*)_(.*)$
RewriteRule ^(.*)_(.*)_(.*)_(.*)_(.*)$ /$1-$2-$3-$4-$5 [L,R=301]

# Three underscores
RewriteCond %{REQUEST_URI} (.*)_(.*)_(.*)_(.*)$
RewriteRule ^(.*)_(.*)_(.*)_(.*)$ /$1-$2-$3-$4 [L,R=301]

# Two underscores
RewriteCond %{REQUEST_URI} (.*)_(.*)_(.*)$
RewriteRule ^(.*)_(.*)_(.*)$ /$1-$2-$3 [L,R=301]

# One underscore
RewriteCond %{REQUEST_URI} (.*)_(.*)$
RewriteRule ^(.*)_(.*)$ /$1-$2 [L,R=301]

Answer 2

Don't do this at the .htaccess level, replace your Joomla links in the database (by using the MySQL REPLACE command), and then create a simple PHP redirect in the defines.php file (you can read more about this file here). You will have better control on your links this way.

Essentially, you will need to have the following code in your defines.php file (replace http:// below with https:// if your site uses https):

<?php
    $currentURL = 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
    if (strpos ($currentURL, '_') !== FALSE){
        $currentURL = str_replace('_', '-', $currrentURL);
        header("HTTP/1.1 301 Moved Permanently"); 
        header("Location: ".$currentURL); 
        exit(); 
    }
?>