*nix Group Permissionify (if it works for me, it should work for my buddies too)

group-permissify.sh

#!/usr/bin/env bash

shared_group="$1" # e.g.: 'admin'

group_exists=`grep "^$shared_group:" /etc/group`

if [ -z $group_exists ]; then
	echo "Error: There seems to be no group by the name of \"$shared_group\" (totally checked out your '/etc/group' file)."
else
	echo "Permissifying within ./ directory..."
	
	echo '	'"Changing group to \"$shared_group\"..."
	sudo chown -R :"$shared_group" .
	
	echo '	'"Setting group read permission for all files with owner read permission..."
	sudo find ./ -perm -u+r -not -perm -g+r -exec chmod -h g+r '{}' \;
	echo '	'"Setting group write permission for all files with owner write permission..."
	sudo find ./ -perm -u+w -not -perm -g+w -exec chmod -h g+w '{}' \;
	echo '	'"Setting group execute permission for all files with owner execute permission..."
	sudo find ./ -perm -u+x -not -perm -g+x -exec chmod -h g+x '{}' \;
	
	echo '	'"Setting setgid bit on directories (to hopefully avoid incorrect group issues in the future)..."
	sudo find ./ -type d -perm -g+w -not -perm -g+s -exec chmod g+s '{}' \;
	
	echo "All permissied up. Enjoy."
fi