Rewrite rule to replace every %20 in the URL with an underscore

Question

I would like my current URLs:

http://example.com/files/528/Rabba%20Ho%20-%20Falak%20Shabir%20Song.html

To look cleaner like this:

http://example.com/files/528/Rabba_Ho_-_Falak_Shabir_Song.html

This is my current .htaccess file:

RewriteRule ^category/([^/]*)/([^/]*)\.html$ /index.php?pid=$1&ht=$2 [L]
RewriteRule ^category/([^/]*)/([^/]*)/([^/]*)\.html$ /index.php?pid=$1&page=$2&ht=$3 [L]
RewriteRule ^category/([^/]*)/([^/]*)/([^/]*)/([^/]*)\.html$ /index.php?sort=$1&pid=$2&page=$3&ht=$4 [L]
RewriteRule ^filedownload/([^/]*)/([^/]*)/([^/]*)\.html$ /fileshow.php?pid=$1&id=$2&ht=$3 [L]

How do I modify it to rewrite the encoded spaces and underscores?

Answer 1

Here is a similar question on StackOverflow: mod_rewrite: replace underscores with dashes

I've modified the answer to replace spaces (decoded %20) with underscore. It works by recursively applying a rewrite rule as long as there are two or more matches, and then once there is only one, a separate rewrite rule does the redirect.

RewriteEngine     On
RewriteRule       ^(/?files/.*/[^/]*?)\s([^/]*?\s[^/]*)$ $1_$2 [N]
RewriteRule       ^(/?files/.*/[^/]*?)\s([^/\s]*)$       /$1_$2 [R=301]

As others have commented, you will need to make sure your application expects underscores in the URL path, and is generating URLs that have the underscore.

Answer 2

First sorry about my bad english. I use this in my PHP apps links:

<?php $theURL = "http://example.com/files/528/Rabba Ho - Falak Shabir Song.html"; ?>

<a href="<?= str_replace( " ", "_", $theURL ); ?>" target="_blank">
    Rabba Ho - Falak Shabir Song
</a>

EDIT: Sorry for last error, i edit now...

The above code returns a URL like:

http://example.com/files/528/Rabba_Ho_-_Falak_Shabir_Song.html.