XAMPP undefined functions

[xiao]

My XAMPP installation doesn't seem to have the following functions installed:
http://php.net/filter
While php.net states that they're included in the default module.
How do I get them in my installation?

I was told to download the PECL zip archive, unzip it, copy the .dll that you want I use into my php extensions folder, and add a line to my php.ini file to load the extension.

But I don't know what that line should look like and which .dll file I would need?

[bradgrafelman]

Assuming you're on Windows, the filter extension should already be included in PHP. If you do a phpinfo(), do you see a table labeled "filter" ? If not, what version of PHP are you running?

[xiao]

Yes, I have that label, I'm running 5.2.2

[bradgrafelman]

If you see that table, then the filter functions should already be available to you and you don't need to install anything.

EDIT: You can test this with the following code:

print_r(filter_list());

If you see an array of filters outputted, then you can use the [man]filter[/man] functions/constants.