$ pwd
/usr/local/src
$ ls -ld .
drwxrwsr-x 5 root staff 4096 May 16 20:36 .
$ ls -l foo.tar.gz
-rw-r--r-- 1 root staff 206574 May 16 20:35 foo.tar.gz
$ sudo tar xf foo.tar.gz
$ ls -ld foo
drwxr-sr-x 7 root staff 4096 May 16 20:36 foo/