How to validate a file with .tar.xz extension?

Yii 2.0 General Discussions
1

How can I limit file upload to .tar.xz extension only ?
So far I have only obtained success for non-composite extensions (.zip, .xz, etc)

Thanks

2

My test with Apache 2.4.43 or PHP 7.4 built in server returns mime type ‘application/x-xz’ using:
echo mime_content_type('test.tar.xz');

3

You’d have to unpack the file and see if it contains a valid tar file (POSIX tar archive).