Need expert help with tricky redirect problem [duplicate]

Question

I actually posted about this years ago, never got anywhere. Did more research, did testing, got something I thought worked and mostly did, but it seems to get bogged down in infinite loops under certain circumstances. I am at my wit's end. Anyone who can help me resolve this, you are my hero for life. :)

The Problem

I run a photo gallery and I changed my website structure a few years ago.

The Old Site

The old structure, an album had a form like this:

http://desktopscenes.com/Name Of Album (Year)/default.html

Individual photo slides were like this:

http://desktopscenes.com/Name Of Album (Year)/slides/Name Of Slide.html

And the actual slide was:

http://desktopscenes.com/Name Of Album (Year)/slides/Name Of Slide.jpg

The New Site

An album is like this:

http://desktopscenes.com/Name_Of_Album_-_Year/index.htm

A photo slide like this:

http://desktopscenes.com/Name_Of_Album_-_Year/slides/Name_Of_Slide.htm

And the photo:

http://desktopscenes.com/Name_Of_Album_-_Year/slides/Name_Of_Slide.jpg

So What I Need to Happen Is:

1. Change all spaces to underscores.
2. Change the year references from " (Year)" to "_-_Year".
3. Change "html" to "htm".
4. Not break anything else. :)

My Attempt

You'd think this would be fairly simple. And in fact I actually got this to work -- most of the time. The problem is that occasionally something sends a request and sends it into an infinite loop.

Here's my code.

RewriteEngine On
Rewritecond %{HTTP_HOST} ^(desktopscenes.com|www.desktopscenes.com)$ [nc]
RewriteRule ^(.*)\s(.*)$ $1_$2 [N,NE]
RewriteRule ^(.*)\((.*)$ $1-_$2 [N,NE]
RewriteRule ^(.*)\)(.*)html$ http://desktopscenes.com/$1$2htm [NE,R=301,L]
RewriteRule ^(.*)\)(.*)jpg$ http://desktopscenes.com/$1$2jpg [NE,R=301,L]

A Clue - Revised!

If 'proper' requests come in as they should, this works fine. I think the problem is if a request comes in that is incorrect. In particular, sometimes I get a request like this on the old site:

http://desktopscenes.com/Name Of Album (Year)/Name Of Slide.jpg

Notice the "slides" folder is missing. I am pretty sure this request created an infinite loop.

ETA: Looking through my logs I am now seeing this is much more common than I thought. I would love a way, if possible, to add the "slides/" folder back in if a request for a .jpg comes in without "slides/" in the URI.

In Closing

Thank you for listening and attempting to help me with this. It has literally been bothering me for years!

Addendum

I have also been changing apostrophes in the original names to dashes. But these are infrequent so they are less important.

Revised Code

This is what I have now

RewriteEngine On
Rewritecond %{HTTP_HOST} ^(desktopscenes.com|www.desktopscenes.com)$ [nc]
RewriteRule ^(Test.*)\s(.*)$ $1_$2 [N,NE]
RewriteRule ^(Test.*)\((.*)$ $1-_$2 [N,NE]
RewriteRule ^(Test.*)\)(.*)/slides/(.*)html$ http://desktopscenes.com/$1$2/slides/$3htm [NE,R=301,L]
RewriteRule ^(Test.*)\)(.*)/slides/(.*)jpg$ http://desktopscenes.com/$1$2/slides/$3jpg [NE,R=301,L]

This handles the case where I have album (year)/subalbum/slides.html or whatnot.

The "Test" is in there so I can test this on a dummy structure without blowing up the rest of the site.

I am still not sure how to handle requests of the form: http://desktopscenes.com/Name Of Album (Year)/Name Of Slide.jpb

That is no "slides". I am not sure what the regex is to NOT find a particular string, I guess I could look that up.

Another Update - Adding back "/slides/"

I don't need to search for "no slides". Since the ones that match "slides" have the "L" suffix they should stop processing once found. (Correct?)

So I was able to add this:

RewriteRule ^(Test.*)\)([^/]*)/(.*)jpg$ http://desktopscenes.com/$1$2/slides/$3jpg [NE,R=301,L]

Which actually adds the "/slides" back in if not present on a JPG request, which is great!

When I tried to do the same for HTML however:

RewriteRule ^(Test.*)\)([^/]*)/(.*)html$ http://desktopscenes.com/$1$2/slides/$3htm [NE,R=301,L]

It doesn't work. Any idea why?

Answer 1

I'm going to close this. The code basically works, there's a more specific question someone may be able to help with, without having to wade through all my rambling.

Thanks for the patience of whoever read this and tried to help.