If you explicitly provide a file by path, then tar doesn't use magic number autodetect, but uses file extension dispatch instead. You would need to pass the da

If you explicitly provide a file by path, then tar doesn't use magic number autodetect, but uses file extension dispatch instead. You would need to pass the data as a stream to force magic number autodetect: <firefox-9.0.1.source.tar.bz2 tar xaf - Does that still work? It doesn't for me. I was using (GNU tar) 1.20 and Debian stable is now at 1.23, but I think that autodetect code went in around 1.18.