Apache’s mod_rewrite is one of the most confusing things to learn but it is an extremely powerful tool. One of the best resources I found was http://www.webforgers.net/mod-rewrite/. Recently I needed to rename a folder on one of the sites I built. The traffic needed to be automatically routed to the new folder to keep all the links to the content valid. To accomplish this, i used a mod rewrite to grab the string after the old folder and move it to the new folder. Below is the content of my .htaccess (located in the root directory with my new folder) file:
RewriteEngine On
RewriteBase /subdir/
RewriteRule ^olddir/?(.*)$ newdir/$1 [R=301,L]
So lets look at it line by line
RewriteEngine onThe RewriteEngine has to be on (obviously).
RewriteBase /subdir/the RewriteBase is the path to the folder containing your .htaccess and the new folder (in this case, “subdir/” would contain “.htaccess and newdir/”). This is relative to the domain. So if you were working with yourdomain.com/newdir/ the RewriteBase would just be “/”.
RewriteRule ^olddir/?(.*)$ newdir/$1 [R=301,L]The RewriteRule takes anything after the request for your old folder (like index.html) and changes the URL to the new folder. “olddir” is the name of your old folder and “newdir” is the name of your new folder. So a request like:
yourdomain.com/subdir/olddir/index.php?var=value
would become
yourdomain.com/subdir/newdir/index.php?var=value
it doesnt matter what comes after the request for the oldir it will get moved to the newdir. It’s pretty obvious that mod_rewrite is a powerful tool but mastering it is a significant challenge. Here’s one down though, and plenty more to go.
-Dre
Tags: .htaccess, apache, mod_rewrite
