I have made a regex for nginx that I want to capture the URL & parameters without the ?. It must only match URL that contain a ?. It must split results into 2 groups.

My regex is: ^(.*)\?(.*)$

It almost works but it catches the trailing slash which breaks some things.

As you can see the trailing / is inside capture group. So I want to either match ? or /? in a non-capturing group depending what is there but it doesn't work as expected:

Updated regex: ^(.*)(?:\/\?|\?)(.*)$

This will always still only match the ? I guess because it looks for smaller match first.

I can't quite conceptualize the right way to drop the training slash from capture group in a single regex.

CodePudding user response：

You can use

^(.*[^\/])?\/?\?(.*)$
^(.*?)\/?\?(.*)$

See the regex demo #1 / regex demo #2.

Details:

The ^(.*[^\/])?\/?\?(.*)$ pattern means:

• ^ - start of string
• (.*[^\/])? - an optional Group 1: any zero or more chars other than line break chars as many as possible, and then a char other than a /
• \/? - an optional / char
• \? - a ? char
• (.*) - Group 2: any zero or more chars other than line break chars as many as possible
• $ - end of string.

The ^(.*?)\/?\?(.*)$ means:

• ^ - start of string
• (.*?) - Group 1: any zero or more chars other than line break chars as few as possible
• \/?\?(.*)$ - an optional /, then a ? char, then Group 2 capturing the rest of the string.