[plt-scheme] Unix Question

["Manning, Mikki ARCENT-QA Contractor" <Mikki.Manning@qatar-emh1.army.mil>]

If I wanted to write a script called "greeting" (the required name for the
script) that gets from UNIX system the current hour and greets the current
user in the following way how would i accomplish this:

ex:
	if the hour is less than 12 p.m. it prints to the screen: "Good
Morning  Mr./Ms." and user's login name;
	else if the hour is less than 17 p.m. it prints to the screen "Good
Afternoon  Mr./Ms." and user's login name;
	else if the hour is greater or equal than 17 p.m. it prints to the
screen "Good Evening Mr./Ms." and user's login name.