Part 2 - .htaccess Commands

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Introduction
In the last part I introduced you to .htaccess and some of its useful features. In this part I will show you how to use the .htaccess file to implement some of these.

Stop A Directory Index From Being Shown

Sometimes, for one reason or another, you will have no index file in your directory. This will, of course, mean that if someone types the directory name into their browser, a full listing of all the files in that directory will be shown. This could be a security risk for your site.

To prevent against this (without creating lots of new ‘index’ files, you can enter a command into your .htaccess file to stop the directory list from being shown:

Options -Indexes

Deny/Allow Certian IP Addresses

In some situations, you may want to only allow people with specific IP addresses to access your site (for example, only allowing people using a particular ISP to get into a certian directory) or you may want to ban certian IP addresses (for example, keeping disruptive memembers out of your message boards). Of course, this will only work if you know the IP addresses you want to ban and, as most people on the internet now have a dynamic IP address, so this is not always the best way to limit usage.

You can block an IP address by using:

deny from 000.000.000.000

where 000.000.000.000 is the IP address. If you only specify 1 or 2 of the groups of numbers, you will block a whole range.

You can allow an IP address by using:

allow from 000.000.000.000

where 000.000.000.000 is the IP address. If you only specify 1 or 2 of the groups of numbers, you will allow a whole range.

If you want to deny everyone from accessing a directory, you can use:

deny from all

but this will still allow scripts to use the files in the directory.

Alternative Index Files

You may not always want to use index.htm or index.html as your index file for a directory, for example if you are using PHP files in your site, you may want index.php to be the index file for a directory. You are not limited to ‘index’ files though. Using .htaccess you can set foofoo.blah to be your index file if you want to!

Alternate index files are entered in a list. The server will work from left to right, checking to see if each file exists, if none of them exisit it will display a directory listing (unless, of course, you have turned this off).

DirectoryIndex index.php index.php3 messagebrd.pl index.html index.htm

Redirection

One of the most useful functions of the .htaccess file is to redirect requests to different files, either on the same server, or on a completely different web site. It can be extremely useful if you change the name of one of your files but allow users to still find it. Another use (which I find very useful) is to redirect to a longer URL, for example in my newsletters I can use a very short URL for my affiliate links. The following can be done to redirect a specific file:

Redirect /location/from/root/file.ext http://www.othersite.com/new/file/location.xyz

In this above example, a file in the root directory called oldfile.html would be entered as:

/oldfile.html

and a file in the old subdirectory would be entered as:

/old/oldfile.html

You can also redirect whole directoires of your site using the .htaccess file, for example if you had a directory called olddirectory on your site and you had set up the same files on a new site at: http://www.newsite.com/newdirectory/ you could redirect all the files in that directory without having to specify each one:

Redirect /olddirectory http://www.newsite.com/newdirectory

Then, any request to your site below /olddirectory will bee redirected to the new site, with the
extra information in the URL added on, for example if someone typed in:

http://www.youroldsite.com/olddirecotry/oldfiles/images/image.gif

They would be redirected to:

http://www.newsite.com/newdirectory/oldfiles/images/image.gif

This can prove to be extremely powerful if used correctly.