$ ls
YKK.kmz
$ gunzip -S "" YKK.kmz 
gunzip: YKK.kmz already exists; do you wish to overwrite (y or n)? y
$ ls
$ ls -la
total 0
drwxr-xr-x    2 dag  dag    68 Dec 13 15:43 .
drwxr-xr-x   94 dag  dag  3196 Dec 13 15:42 ..

Awesome behaviour, gzip!