Htykuut

Context: Google Analytics

Need: A filter that takes given a URI or a URN (yes a URN) it returns everything up to the querystring excluded.

As you can imagine there are multiples variations out of there, which I hope I have covered in full with the list below:

https://sub.domain.com/path/folder/article?l=en >> expected     https://sub.domain.com/path/folder/article

https://sub.domain.com/path/folder/103#3173l=en >> expected     https://sub.domain.com/path/folder/103   

https://sub.domain.com/path/folder/103?#3173l=en >> expected     https://sub.domain.com/path/folder/103

https://sub.domain.com/path/folder/103#?3173l=en

0sub.domain.tld  >> expected sub.domain.tld

sub.domain.tld/  >> expected sub.domain.tld

sub.domain.tld?param=value  >> expected sub.domain.tld

sub.domain.tld/?param=value  >> expected sub.domain.tld

sub.domain.tld?param=value#id  >> expected sub.domain.tld

sub.domain.tld/?param=value#id  >> expected sub.domain.tld

sub.domain.tld/folder  >> expected sub.domain.tld/folder

sub.domain.tld/folder/  >> expected sub.domain.tld/folder

sub.domain.tld/folder?param=value  >> expected   sub.domain.tld/folder

sub.domain.tld/folder/?param=value  >> expected  sub.domain.tld/folder

sub.domain.tld/1/folder  >> expected      sub.domain.tld/1/folder

sub.domain.tld/1/folder/  >> expected     sub.domain.tld/1/folder

2sub.domain.tld/1/folder?param=value

3sub.domain.tld/1/folder/?param=value

4sub.domain.tld#id

5sub.domain.tld/#id

6sub.domain.tld/1#id

7sub.domain.tld/1/#id

The challenge I cannot solve is obtaining a regular expression that matches things in a subgroup that is always the same.

If you have to play around, I have saved a couple of tests in
- https://regex101.com/r/trZl06/1/
- https://regex101.com/r/SetgFn/2

The latter is quite satisfactory at capturing my cases, but as soon as a capturing-group is added in front of the existing matching condition, the group greps even words that are not expected.

I tried also something like ((.*)(?:[/]?.*)|(.*)(?:?.*))|((.*)/$|(.*)) but the resulting subgroups are always different making the reference in the filter view a bit of a mess.

Is there anything you can think of?

You may use

^([^#?]*?)([/?#]??.*|[/#]?#.*)?(/?)$

See the regex demo.

Details

• 
  ^ - start of string


• 
  ([^#?]*?) - Group 1: 0 or more chars other than # and ?, as few as possible


• 
  ([/?#]??.*|[/#]?#.*)? - an optional Group 2: either of the two:
  
  
  
  
  • 
    [/?#]??.* - an optional /, ? or # followed with a ? char and then the rest of the string
  
  
  • 
    | - or
  
  
  • 
    [/#]?#.* - an optional / or # followed with a # char and then the rest of the string
  
  
  
  


• 
  (/?) - Group 3: an optional /
  


• 
  $ - end of string.