Matching a specific string between two forward slashes

I need to find开发者_高级运维 all %20's between two forward slashes.

example.com/book%20/picture1.jpg
example.com/book%20/picture2.jpg
example.com/book%20/picture3.jpg
example.com/pages/picture%20book1.jpg
example.com/pages/picture%20book2.jpg
example.com/pages/picture%20book3.jpg

It should find the first 3 links, not the last 3.

I cant seem to figure it out.

This fulfills the requirement "%20" between two forward slashes

/\/[^/]*%20[^/]*\//

\/       literal "/"
[^/]*    every character except for a slash, zero or more occurences
%20      literal "%20"
[^/]*    every character except for a slash, zero or more occurences
\/       literal "/"

Such an RE could be used for validating, if used for matching it matches the text between two slashes with a %20 including the leading and trailing slash.

If you are using a regex implemenation that supports arbitrarily long lookaround constructs (like .NET) you could use

(?<=.*/)%20(?=.*/)

I tried this one in .Net and it returned the three first links. I am not much of a regex guy, so this can most likely be done much more elegant way than my example.

(\w*\.*)*/(\w*)*%20(\w*)*/(\w*\.*)*

@Lekensteyn was right but skipped escaping forward slashes in the character class [^/]*.

Instead of:

/\/[^/]*%20[^/]*\//

use:

/\/[^\/]*%20[^\/]*\//