Stripping "blog" from wordpress URLs with Regex - regex

Question

I've managed to get myself totally mired in the world of regex and could do with a hand out.
I've recently moved my wordpress install from just the /blog subdomain to the whole site so I need to strip /blog/ from all incoming urls except an exact match as /blog is still the blog.
For example I need:
http://foo.com/blog/bar
http://foo.com/blog/foobar/bar
foo.com/blog/bar
to all lose the /blog/ but I need
http://foo.com/blog
foo.com/blog
to keep theirs.
I'm using the wordpress Redirections plugin to manage this as it tracks 404 errors which put me on to this.
Can anyone help!?

Answer 1

You need to replace \/blog\/(.+) with /$1
Only replacing /blog/ with / would also replace http://foo.com/blog/
Update:
That works perfectly except that my previous previous post structure
was /y/m/d/postname. How would I strip that as well when it's present
but not affect the other redirect when it isn't?
In this case you could use \/blog\/(\d{4}\/\d{2}\/\d{2}\/(.+)).
Result:
url: http://foo.com/blog/2014/03/09/bar
$1: 2014/03/09/bar
$2: bar
Update 2:
In case you wanted to have both ways stripped use \/blog\/(?:\d{4}\/\d{2}\/\d{2}\/)?(.+)
Result:
url: http://foo.com/blog/bar
url: http://foo.com/blog/2014/03/09/bar
$1: bar
url: http://foo.com/blog/tag/sometag
$1: tag/sometag

Answer 2

Why not try simple replace()?. Unless I misunderstood the question, isn't the output shown the same as what you need?
public static void main(String[] args) {
String s = "http://foo.com/blog/bar";
String s1 = "http://foo.com/blog";
System.out.println(s.replace("/blog/", "/"));
System.out.println(s1.replace("/blog/", "/"));
}
O/P :
http://foo.com/bar
http://foo.com/blog