Unix-way
find /target/directory -type f -exec file '{}' \; | grep -i archive:
Пример вывода:
./.minecraft/bin/minecraft.jar: Zip archive data, at least v2.0 to extract
./w2.zip: Zip archive data, at least v2.0 to extract
./.dropbox-dist/setuptools-0.6c11-py2.5.egg: Zip archive data, at least v2.0 to extract
./1.tar: POSIX tar archive (GNU)