from bz

On linux-based machines, save this as the file Makefile

.SILENT: 

me:

a:

sandwich:
ifeq ($(shell id -u), 0)
	echo "Okay"
	# Ordering code goes here
else
	echo "What? Make it yourself."
endif

From the directory in which that file exists, you can now type

make me a sandwich

(which does not work) and

sudo make me a sandwich

(which does). Actually making the sandwich is an exercise left to the reader (although Dominos now makes sandwiches).