To increase reusability of common code, it is possible to include pre-exsting php file(s) in other php files. The syntax is as following
include ("includeme.php");
where "includeme.php" is the name of the PHP file you want to include.
For example, the following is being <echo>'d from an included script:
In addition to including PHP files from your own server using the syntax decsribed above, it is also possible to include files from the internet (other people's servers). In order to do that use the following syntax:
echo file_get_contents("http://www.yahoo.com");
You can also use this syntax to output the content of a text file on your server. In the example below we're going to try and echo the content of another server. It might take a while as it has to get contents from the other server and then store in the local server, but here is the content from weather-forecasts's website.