When you write a post in Wordpress you can set certain custom fields. The default search behaviour of Wordpress is to search only the title and main text of the posts, which makes these custom fields not all that useful. With a little bit of tinkering you can get Wordpress to search any custom fields that you have set, so if you store things like "Author" you can allow people to view all posts by that author by clicking on a link or doing a search. To see more information about Wordpress custom fields see this Wordpress codex site article. Wordpress stores these custom fields in a table called postmeta where each custom field name (called meta_key) is associated with a custom field value (called meta_value).

To randomise an array in PHP use the shuffle() function like this.

$array = range(1, 5);
shuffle($array); // randomise array

There are two limitations to this function. The first is that it completely removes any key association that you may have set up. So the following array.

It is widely known that the data that Alexa offers on visitor numbers is far from accurate, but it is possible to obtain an XML feed from Alexa that allows you to find out all of the data that Alexa offers, which is more than just their visitor numbers. Passing the correct parameters to this feed you can find out related links, contact and domain information, the Alexa rank, associated keywords and Dmoz listings.

As an example here is a feed URL for getting information about the bbc.co.uk page.

So to get information about any site all you have to do is pass the correct URL to this address.

To get this information in a usable form with PHP you can use the curl functions. To download the Alexa feed into PHP use the following code:

The str_word_count() function in PHP does exactly what is says it does. The default of this function is to simply count the number of words present. Take the following string.

If we pass this to the str_word_count() function with no other parameters we get the number of words.

Using a simple .htpasswd to password protect a directory or website is fine if you only have a few users, and they don't change very much. However, this quickly becomes impossible to maintain if you have lots of users. For example, if you wanted to secure access to the company Intranet you might spend quite some time trying to update your .htpasswd file. The best way to do this is to transfer all of the user administration over to an LDAP server and then get Apache to communicate with this directly. The Active Directory (AD) system that Microsoft uses allows LDAP communications, and as this is in use across many company networks it is an ideal candidate to use.

You first need to set of the LDAP modules on your Apache server. Uncomment or add the following lines in your http.conf file. You will need to make sure that the files actually exist as well.

If you have programmed in PHP for any amount of time then you will be farmiliar with the if statement. The syntax is as follows:

Sometimes in PHP you will have to do some things that might take a little time. You will therefore have a little trouble with users closing the browser or moving to another page before the script has finished. In this case you will want to either continue to execute the script just shut it down depending on what the user has done.

PHP will not detect that the user has aborted the connection until an attempt is made to send information to the client. Simply using an echo statement does not guarantee that information is sent. Use the flush() function after the echo call to force PHP to sent output information to the browser.

To run the script to the end no matter what the user has done use the ignore_user_abort() function with the parameter of true.

Letting the user now that something in the background is working is an essential part of website usability. If nothing at all happens then the user will more than likely either try again or go elsewhere. A good way of doing this is to have a little bit of text that says "Working" and animate dots behind it. Here is a function that will do this.

PHP keeps certain variables to do with server and networking in an associative array called SERVER. To find out the remote address of a user you can use the array identifier REMOTE_ADDR. This is used in the following manner.

This IP address can be passed into the gethostbyaddr() function to find out host name associated with the specified IP address.

After installing PHP on Apache you can use the php.ini file to set various different options to do with PHP. When Apache starts it uses what is contained in this file to set up and run PHP.

On both Windows, Unix and Linux systems Apache will look in a number of default locations for the php.ini file before giving up. You can explicitly tell Apache 2.x where to look for the file by using the PHPIniDir directive in the http.conf file.

#
# This is the directory containing php.ini
#
PHPIniDir "/usr/local/apache/conf"

For Apache 1.3.x this can be set using the SetEnv PHPRC directive.