add file type extension using .htaccess in subdirectory?

Question

I want to map links like https://website.com/test/STRING to https://website.com/test/STRING.png , how to do it with .htaccess?

Options All -Indexes -MultiViews
RewriteEngine on
RewriteBase /test/

RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{DOCUMENT_ROOT}/test/%1.png -f
RewriteRule ^([^/]+)/?$ /$1.png [NC,L]

but it is not working

Answer 1

I guess this is what you are looking for:

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} ^/test/([^/]+)/?$ 
RewriteCond %{DOCUMENT_ROOT}/test/%1.png -f
RewriteRule ^ /test/%1.png [END]

There are alternatives obviously, this is just a suggestion. In case you receive an internal server error (http status 500) using the rule above then chances are that you operate a very old version of the apache http server. You will see a definite hint to an unsupported [END] flag in your http servers error log file in that case. You can either try to upgrade or use the older [L] flag, it probably will work the same in this situation, though that depends a bit on your setup.

This rule will work likewise in the http servers host configuration or inside a dynamic configuration file (".htaccess" file). Obviously the rewriting module needs to be loaded inside the http server and enabled in the http host. In case you use a dynamic configuration file you need to take care that it's interpretation is enabled at all in the host configuration and that it is located in the host's DOCUMENT_ROOT folder.

And a general remark: you should always prefer to place such rules in the http servers host configuration instead of using dynamic configuration files (".htaccess"). Those dynamic configuration files add complexity, are often a cause of unexpected behavior, hard to debug and they really slow down the http server. They are only provided as a last option for situations where you do not have access to the real http servers host configuration (read: really cheap service providers) or for applications insisting on writing their own rules (which is an obvious security nightmare).