Very strange php include behavior.. - php

Question

I am experiencing some very strange behavior when including a php file.
I need to load a script that is not on the same domain as the page that will be calling it.
I have already created a system that works using cURL, but I just recently found out that many of the sites that will need to have access to this script, do not have cURL installed.
I did, however, notice that these sites have allow_url_fopen set to on. With this knowledge I got started creating a new system that would let me just include the script on the remote site.
Just testing this out, I coded the script test.php as follows:
<?php
echo("test");
?>
I include this script on the remote page using:
<?php
include("http://mydomain.com/script.php");
?>
and it works no problem and "test" is printed at the top of the page.
However, if I add a function to the script and try to call the function from the page, it crashes.
To make it worse, this site has php errors turned off and I have no way of turning it on.
To fully make sure that I didn't just mess up the code, I made my test.php look like this:
<?php
function myfunc()
{
return "abc";
}
?>
Then on the page including the file:
<?php
include("http://mydomain.com/script.php");
echo(myfunc());
?>
And it crashes.
Any ideas would be greatly appreciated.

Answer 1

This is not odd behavior, but since you load the file over the internet (note in this case the World Wide Web), the file is interpreted before it is sent to your include function.
Since the script is interpreted no functions will be visible, but only the output of the script.
Either load it over FTP or create an API for the functions.

Answer 2

My guess: The PHP of http://mydomain.com/script.php is interpreted by the web server of mydomain.com. All you're including is the result of that script. For a simple echo("test"), that's "test". Functions do not produce any output and are not made available to the including script. Confirm this by simply visiting http://mydomain.com/script.php in your browser and see what you get. You would need to stop mydomain.com from actually interpreting the PHP file and just returning it as pure text.
But: this sounds like a bad idea to begin with. Cross-domain includes are an anti-patterns. Not only does it open you up to security problems, it also makes every page load unnecessarily slow. If cross-domain inclusions is the answer, your question is wrong.

Answer 3

You are including the client side output from test.php rather than the server-side source code. Rename test.php to test.phpc to prevent executing the script. However this is dangerous out of security point of view.