Redirecting i/o streams

[VERACSD at usc-isi.arpa]

	I am writing a micro-shell based on Bach's discussion in "Design of the
Unix Operating System" (pp. 233-235).  I want to compare his algorithms with
the source code.  How do I go about finding it?  (I am using using 4.3 BSD, and
may be able to access Xinu source as well).
	Also, how does one go about redirecting the standard i/o streams 
(i.e. stdin, stdout & stderr) in C to a null device?  I want to locally bind
their vals to a null device.

Advance thanks,
ck