Rewrite URL if page exists in a sub folder - regex

Question

I was wondering if there is a way to achieve this sort of URL rewriting;
RewriteRule ^example-link-1?$ /blog/example-link-1 [NC,L]
RewriteRule ^example-link-2?$ /blog/example-link-2 [NC,L]
RewriteRule ^example-link-3?$ /blog/example-link-3 [NC,L]
RewriteRule ^example-link-4?$ /blog/example-link-4 [NC,L]
where you go directly to a link such as example.com/example-link-1 and you are actually shown content from example.com/blog/example-link-1, but without the need for a new rule per page i add. Is there a dynamic way to do this in the htaccess? ie;
IF exists('blog/'+pageURI)
THEN rewrite to 'blog/'+pageURI but keep the uri without 'blog/' in it.

Answer 1

Yes sure you can do:
RewriteRule ^(example-link-[1234])/?$ /blog/$1 [NC,L]
for above 4 rules. But in general you can do this:
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{DOCUMENT_ROOT}/blog/$1 -f
RewriteRule ^(.+?)/?$ /blog/$1 [NC,L]
This will rewrite to /blog/something if /blog/something exists while keeping the same URI without /blog/.