Wordpress rewrite rule for custom PHP page - php

Question

I have created a PHP page which I'm using an include plugin for in wordpress.
So when I visit domain.com/kb it shows me the included PHP file which works fine.
I want to make the URL pretty so I tried adding this to the top of the php file:
add_rewrite_rule('^kb/([^/]*)/([^/]*)/?','index.php?page_id='.get_the_ID().'&category=$matches[1]&sequence=$matches[2]','top');
But when I visit domain.com/kb/123 is just removes the 123 and leaves domain.com/kb/
Ultimately, I want to be able to visit domain.com/kb/123/456 where I can read "123" and "456" as separate variables.

Answer 1

The current regex you have doesn't match kb/123, because it looks for a mandatory 2nd /. (marked in blue)
I'm gonna ignore that and go for your end-goal.
Going by this answer,
i've come up with the following solution:
function wpd_foo_rewrite_rule() {
add_rewrite_rule(
'^kb/(.*?)/([^/]*)',
'index.php?page_id='.get_the_ID().'&category=$matches[1]&sequence=$matches[2]',
'top'
);
}
add_action( 'init', 'wpd_foo_rewrite_rule' );
let's go over the regex -
that ?, in that context, means "lazy". match as few characters as possible until you hit the following char (/). (then, of course, we save it in a capture group).
Afterwards, let's deal with the 2nd parameter.
The following will take everything between kb/ and the 1st / (well, 1st after kb's) into the 1st capture group, (attention! the 1st / must exist, otherwise it isn't a match),
and everything after the 1st /, into the 2nd capture group.
this assumes you won't have any other "/" parameters (they'll all be in capture group 2) and that you won't have any query parameters (same thing).
if you want to utilize your "any char except /, that's fine too.
As a rule - never trust user input, always sanitize it. be on the lookout for ways to trick your plugin into loading files it shouldn't, inserting malicious data into storage (DB etc..), or querying data it shouldn't
btw - screenshots taken from regexr