Let's start by exposing the case. I have a web created in drupal that I have to modify. With an absurd amount of content, then, I need to change a URL of the src of the images by another URL and I thought that the best solution would be to do it with htaccess.
Suppose I have a URL such that: www.example.com/event/april-2019/intranet/content/big_Imagen11935.jpg
And I must point to the URL such that: www.example.com/sites/default/files/intranet/content/big_Imagen11935.jpg
Obviously I have to point out that the route could be changed and that instead of being april-2019 it is a different one.
So, I have created the following code:
RewriteCond% {DOCUMENT_ROOT}% {REQUEST_URI}! -F
RewriteCond% {SCRIPT_FILENAME} ^(.*)\.(Gif|jpe?G|png|bmp)$
RewriteRule ^intranet/(.*)$ http://www.example.com/sites/default/files/intranet/$1 [NC, L]
But of course, with this, what I do is pick up from "intranet" until the end and send it to the next route, but it stays stored "/event/april-2019/"
I do not know, if I have to use then, Redirect (but being an SRC to an image, I do not know if it's the best option)
Maybe another option is to create a script to a .php where you can change the URL and forward it to .htaccess?
I speak from ignorance, since I have been investigating about only a few days