PHP free file content analyzer library / function

PHP free file content analyzer library / function

I was wondering if you know about any good and accurate PHP library or
file I can include in my script in order to analyse the content of X file
and then check if it is an especific type like .doc, .docx .jpg, etc.
I know PHP offers a big number of libraries that we could use to check
them, but they're not that accurate at all, some just checks the file
extension or the file header (they don't even know if the file is broken
or not)
What I request is for something very accurate, simple and faster (probably
I'm requesting too much) but any link or suggestion will be accepted and
appreciated, Thank you!