Question

I’m basically not in the clue about regex but I need a regex statement that will recognise anything after the / in a URL.

Basically, i’m developing a site for someone and a page’s URL (Local URL of Course) is say (http://)localhost/sweettemptations/available-sweets. This page is filled with custom post types (It’s a WordPress site) which have the URL of (http://)localhost/sweettemptations/sweets/sweet-name.

What I want to do is redirect the URL (http://)localhost/sweettemptations/sweets back to (http://)localhost/sweettemptations/available-sweets which is easy to do, but I also need to redirect any type of sweet back to (http://)localhost/sweettemptations/available-sweets. So say I need to redirect (http://)localhost/sweettemptations/sweets/* back to (http://)localhost/sweettemptations/available-sweets.

If anyone could help by telling me how to write a proper regex statement to match everything after sweets/ in the URL, it would be hugely appreciated.

Answer 1

To do what you ask you need to use groups. In regular expression groups allow you to isolate parts of the whole match.

for example:

input string of: aaaaaaaabbbbcccc 

regex: a*(b*) 

The parenthesis mark a group in this case it will be group 1 since it is the first in the pattern.

Note: group 0 is implicit and is the complete match.

So the matches in my above case will be:

group 0: aaaaaaaabbbb
group 1: bbbb

In order to achieve what you want with the sweets pattern above, you just need to put a group around the end.

possible solution: /sweets/(.*)

the more precise you are with the pattern before the group the less likely you will have a possible false positive.

If what you really want is to match anything after the last / you can take another approach:

 possible other solution: /([^/]*)

The pattern above will find a / with a string of characters that are NOT another / and keep it in group 1. Issue here is that you could match things that do not have sweets in the URL.

Note if you do not mind the / at the beginning then just remove the ( and ) and you do not have to worry about groups.

I like to use http://regexpal.com/ to test my regex.. It will mark in different colors the different matches.

Hope this helps.

I may have misunderstood you requirement in my original post.

if you just want to change any string that matches
(http://)localhost/sweettemptations/sweets/*

into the other one you provided (without adding the part match by your * at the end) I would use a regular expression to match the pattern in the URL but them just blind replace the whole string with the desired one:
(http://)localhost/sweettemptations/available-sweets

So if you want the URL:

  http://localhost/sweettemptations/sweets/somethingmore.html

to turn into:

  http://localhost/sweettemptations/available-sweets

and not into:

  localhost/sweettemptations/available-sweets/somethingmore.html

Then the solution is simpler, no groups required :).

when doing this I would make sure you do not match the “localhost” part. Also I am assuming the (http://) really means an optional http:// in front as (http://) is not a valid protocol prefix.

so if that is what you want then this should match the pattern:

(http://)?[^/]+/sweettemptations/sweets/.*

This regular expression will match the http:// part optionally with a host (be it localhost, an IP or the host name). You could omit the .* at the end if you want.

If that pattern matches just replace the whole URL with the one you want to redirect to.