'du -hs *' on Mac failing with "du: illegal option -- n"
You probably have a file whose name begins with -n:
MyMac:~ user$ du -hs *
4.9G Applications
1.1G Desktop
2.2G Documents
954M Downloads
3.3G Library
2.4M Movies
7.8G Music
29G Pictures
1.9G Public
MyMac:~ user$ touch ./-none
MyMac:~ user$ du -hs *
du: illegal option -- n
Try du -hs -- *.