Assuming that you are over-writing your permalinks, you won’t be able to do that even as the file is inside the theme folder. This is because of the fact of Wordpress, when with permalinks enabled, treat your routes through RewriteRules in the .htaccess. Assuming you go to the admin panel and set your Urls to be, for example, based on the post name, the following .htaccess is created (I removed the examples of a WP instance I have running on http://localhost/wp_testes/):
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /wp_testes/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /wp_testes/index.php [L]
</IfModule>
# END WordPress
That answer, in the SO gringo, gives an excellent explanation of how these rules work. Adding this to the Hierarchy of Templates from WP, it is easy to conclude that all requests made within your WP instance (in my case, from /wp_testes/ forward), will be routed according to these rules, preventing direct access. If your file teste.php not according to the template rules, the house will fall.
Solutions
Do not use permalinks.
It’s dirty, I know. Your Urls will look terrible, but it will allow you direct access to your file. In my case, I disabled the permalinks, and made a direct access to http://localhost/wp_testes/wp-content/themes/twentyfifteen/teste.php?teste=123, where teste.php contained this very complicated instruction:
<?php echo $_GET['teste']; ?>
and the result, as expected, was
123
Put your file on root in Wordpress
Filing teste.php in the folder where WP files are located (in my case, inside the folder /wp_testes), permalink rules should not affect your requests. In this case, I made the request http://localhost/wp_testes/teste.php?teste=123 (with permalinks enabled) and got the expected result.
I don’t know if you are necessarily developing a theme, and whether or not you can include files in the WP root. I believe you are limited to these two solutions. But the sum of the two (permalinks with the file within theme), I think there is no way.
Are archives
.phpthat are in the theme folder, and you want to do something likearq.php?param=1? That’s it?– Caio Felipe Pereira
Do you want this . php to use the functions provided by WP? Or does this . php have code that does not depend on WP?
– P. R. Ribeiro
Calo Felipe, are files
.phpyes! And the parameter is type that you made! P. R. Ribeiro that . php depends on WP only for global $wpdb.– Lollipop
Guys, the problem is just that! Can’t get a GET Arq.php? param=1 DESSE Arq.php (which is part of WP) to another arq2.php, which is inside the theme, but is not "run" on the front!
– Lollipop
when vc runs this file directly at the url, it works or rolls a
404? (I’m kicking the404)– Caio Felipe Pereira
Works for wordpress pages, posts, etc... But for that external file not.
– Lollipop
I THINK this is because of permalinks. How you try to access the file directly, via
http://dominio.com.br/arq.php?param=1, he interprets this path as a page, which in its structure does not exist. And direct access to it, viawp_content/themes/tema/arq.phpis blocked. I think the solution is to host it or outside the theme, or create it as a wordpress page template even...– Caio Felipe Pereira
@Lollipop, if you still have interest in this question, can you edit it to add details? . . . . Comments are not the way to improve a question. Thanks!
– brasofilo
@brasofilo, was edited and offered a reward to those who give the best answer.
– Lollipop
What I don’t understand is the button that stays on
page.phpand has to run something unrelated to WP onarquivo.php... gives the impression that it can be solved with an AJAX request, but without knowing the relationship, it is difficult to say if this is it...– brasofilo