The error is caused from the fact you didn't use a string for the filename, and PHP understood the dot as being the concatenation operator; as such, because there wasn't any value before the operator, PHP gave you an error saying it found the concatenation operator in the wrong place.
As kalabro said, the correct code is the following one:
<?php session_start(); ?>
<?php require_once('./classes/MaterialUtil.class.php');
$mUtil = new MaterialUtil();
?>
This is the part of the answer that is not strictly related to Drupal.
What you are doing is not what I would suggest to do, for two reasons:
- You are putting the "classes" directory in the wrong place. Those files are not related to the theme being enabled, but they are related to the page being viewed. Even if you have a single theme, and users are not allowed to select a theme for themselves, it still wrong to put those files in a theme directory.
Putting the files in the directory containing a theme, which will needs to be updated when a new version is available, could cause you to lose the additional files you added, if you are not careful.
- Executing PHP through
eval()
to, e.g., get content to show in a node is not something that you should do. This is because:
- As you have used the PHP filter for the node, the node becomes only editable to a restricted group of users. (I would not suggest to allow untrusted users to use PHP as input format)
- When you have PHP code that you need to execute, it is always better to create a custom module that is enabled for the site.
If you were trying to include a PHP file from inside a module, then you should use module_load_include(), instead of require_once()
, as already suggested by marcvangend.