Help with Regex to match and rewrite URI

I need to have a RegEx that will match a URI like this based on the subdomain "blog"--

http://blog.foo.com/2010/06/25/city-tax-sale/

and redirect like this (getting rid of the subdomain and numbers/date)--

http://foo.c开发者_Python百科om/city-tax-sale/

where the last bit "city-tax-sale" would be a wildcard. So basically any incoming URI that starts with 'blog.foo.com' would be redirected to 'foo.com' + 'whatever is at the end of the above URI after the three sub paths with numbers.

I hope that makes sense. Just trying to create one redirect instead of writing every single one.

This will explicitly match your date format, rather than any series of digits and slashes:

RewriteCond %{HTTP_HOST} ^blog\.foo\.com$ [NC]
RewriteRule ^/\d{4}/\d{2}/\d{2}/(.*)$ http://foo.com/$1 [L,R=301]

The regex part can be broken does to:

^      # start of non-domain url
/\d{4} # slash followed by 4 digits
/\d{2} # slash followed by 2 digits
/\d{2} # slash followed by 2 digits
/      # closing slash
(.*)   # rest of the url, captured to group 1
$      # end of url

With the $1 in the replacement being group 1.

In the options part:
L is for "Last" - tells it to not bother looking at other rules.
R=301 is for Redirect with 301 header, which means permanent redirect (just R would send a temporary 302 header)

The RewriteCond bit performs a case-insensitive (NC option) check on the HTTP_HOST header (supplied by user/client) and if it starts blog.foo.com it performs the rewrite, otherwise it doesn't.

RewriteCond %{HTTP_HOST} ^blog.foo.com [NC] 
RewriteRule ^(\d+/)+(.*)/?$ http://foo.com/$2 [L,R=301]

You can try this:

/http:\/\/blog\..*\.[a-zA-Z]{2,5}\/[0-9]{4}\/[0-9]{2}\/[0-9]{2}\/(.*)\//