Htaccess - remove .php extension and keep query - apache

Question

I've tried to remove the .php extension and keep the id query parameter, but I get a 404 error.
This is the URL:
example.com/folder/file.php?q=123
And I want it to be:
example.com/folder/file/123
Here is my .htaccess file:
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
RewriteRule ^$1/(.*)$ /$1.php?q=$2

Answer 1

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]
This would internally rewrite the URL from /folder/file/123 to /folder/file/123.php, which is obviously going to result in a 404. It would be preferable to test that the corresponding .php file exists, rather than testing that the request does not already map to a file.
I'm assuming the q URL parameter always takes a numeric value.
Try the following instead:
# Rewrite "/folder/<file>/<123>" to "/folder/<file>.php?q=<123>"
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^([^.]+)/(\d+)$ $1.php?q=$2 [L]
The NC flag is not required.
RewriteRule ^$1/(.*)$ /$1.php?q=$2
This rule doesn't make sense and is redundant.

Answer 2

Assuming last path component makes query parameter q, you can use this rule:
RewriteEngine On
# ignore all files and directories from rewrite
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
# Add .php extension and use last component as parameter q
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^(.+)/([\w-]+)/?$ $1.php?q=$2 [L,QSA]
# Add .php extension
RewriteCond %{DOCUMENT_ROOT}/$1.php -f
RewriteRule ^(.+?)/?$ $1.php [L]