how to write regex starts and ends with particular string?

Question

How to write regex for this paricular situation. Here letters in [] is not fixed but letters without [] is fixed.

http://www.abc.com/fixed/[any small letters]/[anyletters]/fixed.html

Answer 1

http://www.abc.com/fixed/[a-z]+/[a-zA-Z]+/fixed.html

Possibly change to a more forgiving:

http://www.abc.com/fixed/[a-z]+/[^/]+/fixed.html

Answer 2

You can use lookarounds for that. One problem may be that they are not available in every language. For instance Javascript has only positive lookahead.

Oh, you mean something different... try this:

http://www.abc.com/fixed/[a-z]+/[\w\D^_]+/fixed.html