Reg Ex left padding with zeros

Question

I have product image URLs: eg. www.example.com/product_images/12345/large.jpg

Now, due to the 'ext3 server' i have a 32,000 file per folder limit, and guess what, i'm very close to having 32,000 products. I can't change the server.

I don't want the URL itself to change so was looking to create a reg ex that I could use in either an AliasMatch to produce the following...

www.example.com/product_images/1/large.jpg => www.example.com/new_product_images/0000/0001/large.jpg

and

www.example.com/product_images/123456/large.jpg => www.example.com/new_product_images/0012/3456/large.jpg

I envisage it padding the number to 8 characters with leading zeros, and then chopping it in half. but my reg ex skill aren't that great... I'm stuck with the padding.

thank you for your time!

Jon.

Answer 1

If you really want padding, you could do this with multiple rules, matching various lengths

RewriteRule ^/product_images/(.{1})(.{4})/(.*)$ new_product_images/000$1/$2/$3
RewriteRule ^/product_images/(.{2})(.{4})/(.*)$ new_product_images/00$1/$2/$3
RewriteRule ^/product_images/(.{3})(.{4})/(.*)$ new_product_images/0$1/$2/$3
RewriteRule ^/product_images/(.{4})(.{4})/(.*)$ new_product_images/$1/$2/$3

Or, just have your folders be 1 or 2 or 3 characters (no padding) and use 1 rule for everything.

RewriteRule ^/product_images/(.+)(.{4})/(.*)$ new_product_images/$1/$2/$3

This would map

• 12345 -> /1/2345
• 123456 -> /12/3456
• 1234567 -> /123/4567
• 12345678 -> /1234/5678

This doesn't keep the folders in order, but its a simpler rule.

You could also use a fixed length prefix - for example, anything that starts with a single digit is in a different folder. Here's an example with 2 digits

This would map

• 123 -> /12/3
• 12345 -> /12/345
• 123456 -> /12/3456
• 234567 -> /23/4567
• 2345678 -> /23/45678

Using this, 2 characters cuts your problem by a factor of 100.

The only problem is IDs less than 100 - one solution might be to leave those in the existing folder (product_images), and your RewriteRule only applies to IDs 100+.

RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^/product_images/(..)(.+)/(.*)$ new_product_images/$1/$2/$3