Redirects

Ever go through the nightmare of changing significantly portions of your site, then having to deal with the problem of people finding their way from the old pages to the new? It can be nasty. There are different ways of redirecting pages, through http-equiv, javascript or any of the server-side languages. And then you can do it through htaccess, which is probably the most effective, considering the minimal amount of work required to do it.

htaccess uses redirect to look for any request for a specific page (or a non-specific location, though this can cause infinite loops) and if it finds that request, it forwards it to a new page you have specified:

Redirect /olddirectory/oldfile.html http://yoursite.com/newdirectory/newfile.html

Note that there are 3 parts to that, which should all be on one line : the Redirect command, the location of the file/directory you want redirected relative to the root of your site (/olddirectory/oldfile.html = yoursite.com/olddirectory/oldfile.html) and the full URL of the location you want that request sent to. Each of the 3 is separated by a single space, but all on one line. You can also redirect an entire directory by simple using Redirect /olddirectory http://yoursite.com/newdirectory/

Using this method, you can redirect any number of pages no matter what you do to your directory structure. It is the fastest method that is a global affect.

In order to specify your own ErrorDocuments, you need to be slightly familiar with the server returned error codes. (List to the right). You do not need to specify error pages for all of these, in fact you shouldn't. An ErrorDocument for code 200 would cause an infinite loop, whenever a page was found...this would not be good.

You will probably want to create an error document for codes 404 and 500, at the least 404 since this would give you a chance to handle requests for pages not found. 500 would help you out with internal server errors in any scripts you have running. You may also want to consider ErrorDocuments for 401 - Authorization Required (as in when somebody tries to enter a protected area of your site without the proper credentials), 403 - Forbidden (as in when a file with permissions not allowing it to be accessed by the user is requested) and 400 - Bad Request, which is one of those generic kind of errors that people get to by doing some weird stuff with your URL or scripts.

In order to specify your own customized error documents, you simply need to add the following command, on one line, within your htaccess file:

ErrorDocument code /directory/filename.ext
or
ErrorDocument 404 /errors/notfound.html
This would cause any error code resulting in 404 to be forward to yoursite.com/errors/notfound.html

Likewise with:
ErrorDocument 500 /errors/internalerror.html

You can name the pages anything you want (I'd recommend something that would prevent you from forgetting what the page is being used for), and you can place the error pages anywhere you want within your site, so long as they are web-accessible (through a URL). The initial slash in the directory location represents the root directory of your site, that being where your default page for your first-level domain is located. I typically prefer to keep them in a separate directory for maintenance purposes and in order to better control spiders indexing them through a ROBOTS.TXT file, but it is entirely up to you.

If you were to use an error document handler for each of the error codes I mentioned, the htaccess file would look like the following (note each command is on its own line):

ErrorDocument 400 /errors/badrequest.html
ErrorDocument 401 /errors/authreqd.html
ErrorDocument 403 /errors/forbid.html
ErrorDocument 404 /errors/notfound.html
ErrorDocument 500 /errors/serverr.html

You can specify a full URL rather than a virtual URL in the ErrorDocument string (http://yoursite.com/errors/notfound.html vs. /errors/notfound.html). But this is not the preferred method by the server's happiness standards.

You can also specify HTML, believe it or not!

ErrorDocument 401 "<body bgcolor=#ffffff><h1>You have
 to actually <b>BE</b> a <a href="#">member</A> to view 

this page, Colonel!

The only time I use that HTML option is if I am feeling particularly saucy, since you can have so much more control over the error pages when used in conjunction with xSSI or CGI or both. Also note that the ErrorDocument starts with a " just before the HTML starts, but does not end with one...it shouldn't end with one and if you do use that option, keep it that way. And again, that should all be on one line, no naughty word wrapping!

Kaynak www.javascriptkit.com/howto/htaccess.shtml