List groups in directory tree

# Check directory tree (recursively) and print every group that is found
# Feel free to use it for whatever you want -even for creating
# cyborg-shark with atomic desintegrator that destroy the world.

ls -laR | sed -r -e 's/  +/ /g' -e 's/^\..*//g' -e 's/^[a-z]+ [0-9]+$//g' |cut -s -d" " -f 4|uniq