PHP包含奇怪的行为

Question

I am working on a client site (PHP) and there is a very strange behavior. Using include, include_once, require, or require_once also seems to pull in other content that should not be there at all. Has anyone heard of anything like this?

Even if the include file is empty or has just some text on it, the behavior persists. Could this be some kind of setting / global behavior?

Thank you

For example:

<?php require_once('dir/subdir/file.php'); ?>

Answer 1

You should always use absolute paths. It's the only reliable way to reference files.

<?php require_once(__DIR__ . '/dir/subdir/file.php'); ?>

Or on PHP 5.2:

<?php require_once(dirname(__FILE__) . '/dir/subdir/file.php'); ?>

Answer 2

The include/require function work by copying the contents of the required file to the placeholder where the function is called. If the included file is empty, then empty is what is copied. If you have content included that you dont recognize it can mean that your include path maybe is pointing to somewhere else than what are you thinking, or maybe the included file is including some extra files in his turn.

As global settings there is a global php include path specified in php.ini where people add libraries usually or global scripts. By default it should not contain things that affect your scripts.

If the file isn't found in the include_path, include will finally check in the calling script's own directory and the current working directory before failing.