How does RewriteBase work in .htaccess

Question

I have seen this in a few .htaccess examples

RewriteBase /

It appears to be somewhat similar in functionality to the <base href=""> of HTML.

I believe it may automatically prepend its value to the beginning of RewriteRule statements (possibly ones without a leading slash)?

I could not get it to work properly. I think it's use could come in very handy for site portability, as I often have a development server which is different to a production one. My current method leaves me deleting portions out of my RewriteRule statements.

Can anyone explain to me briefly how to implement it?

Thanks

Answer 1

RewriteBase is only useful in situations where you can only put a .htaccess at the root of your site. Otherwise, you may be better off placing your different .htaccess files in different directories of your site and completely omitting the RewriteBase directive.

Lately, for complex sites, I've been taking them out, because it makes deploying files from testing to live just one more step complicated.

Answer 2

In my own words, after reading the docs and experimenting:

You can use RewriteBase to provide a base for your rewrites. Consider this

# invoke rewrite engine
    RewriteEngine On
    RewriteBase /~new/

# add trailing slash if missing
    rewriteRule ^(([a-z0-9\-]+/)*[a-z0-9\-]+)$ $1/ [NC,R=301,L]

This is a real rule I used to ensure that URLs have a trailing slash. This will convert

http://www.example.com/~new/page

to

http://www.example.com/~new/page/

By having the RewriteBase there, you make the relative path come off the RewriteBase parameter.