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.tutorial-on.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.tutorial-on.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:
This can prove to be extremely powerful if used correctly.
Although there are many uses of the .htaccess file, by far the most popular, and probably most useful, is being able to relaibly password protect directories on websites. Although JavaScript etc. can also be used to do this, only .htaccess has total security (as someone must know the password to get into the directory, there are no 'back doors')
The .htaccess File
Adding password protection to a directory using .htaccess takes two stages. The first part is to add the appropriate lines to your .htaccess file in the directory you would like to protect. Everything below this directory will be password protected:
AuthName "Section Name"
AuthType Basic
AuthUserFile /full/path/to/.htpasswd
Require valid-user
There are a few parts of this which you will need to change for your site. You should replace "Section Name" with the name of the part of the site you are protecting e.g. "Members Area".
The /full/parth/to/.htpasswd should be changed to reflect the full server path to the .htpasswd file (more on this later). If you do not know what the full path to your webspace is, contact your system administrator for details.
The .htpasswd File
Password protecting a directory takes a little more work than any of the other .htaccess functions because you must also create a file to contain the usernames and passwords which are allowed to access the site. These should be placed in a file which (by default) should be called .htpasswd. Like the .htaccess file, this is a file with no name and an 8 letter extension. This can be placed anywhere within you website (as the passwords are encrypted) but it is advisable to store it outside the web root so that it is impossible to access it from the web.
Entering Usernames And Passwords
Once you have created your .htpasswd file (you can do this in a standard text editor) you must enter the usernames and passwords to access the site. They should be entered as follows:
username:password
where the password is the encrypted format of the password. To encrypt the password you will either need to use one of the premade scripts available on the web or write your own. There is a good username/password service at the KxS site which will allow you to enter the user name and password and will output it in the correct format.
For multiple users, just add extra lines to your .htpasswd file in the same format as the first. There are even scripts available for free which will manage the .htpasswd file and will allow automatic adding/removing of users etc.
Accessing The Site
When you try to access a site which has been protected by .htaccess your browser will pop up a standard username/password dialog box. If you don't like this, there are certain scripts available which allow you to embed a username/password box in a website to do the authentication. You can also send the username and password (unencrypted) in the URL as follows:
http://username:password@www.tutorial-on.com/directory/
Summary
.htaccess is one of the most useful files a webmaster can use. There are a wide variety of different uses for it which can save time and increase security on your website.
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