That extract function seems redundant. GNU tar already auto-detects the compression format of the archive, so `tar xvf archive.tar.xz` will work as expected (th

That extract function seems redundant. GNU tar already auto-detects the compression format of the archive, so `tar xvf archive.tar.xz` will work as expected (the J flag is not needed.) bsdtar does the same, and it supports formats other than tar, so `bsdtar xvf archive.zip` works too. These tools use the content of the file rather than the file extension, so they should be more reliable.