Getting hold of SYSTEM output.

[gjw@grucis.anu.OZ.AU (Graham Williams)]

Is there a simple way of getting a hold of (as a string) the result of
a SYSTEM function call? For example, I want to find out what host I
am running on (not always obvious) and use this to do different things.
In KCL (SYSTEM "hostname") calls the shell with any output echoed, and
returns the exit status. I would like a function SYSTEM-TO-STRING 
to grab hold of this output!
Viz: (SETF MACHINE-INSTANCE (SYSTEM-TO-STRING "hostid"))

Any hints?

Graham Williams, gjw@anucsd.anu.oz.au
Dept Computer Science, Australian National University,
GPO Box 4, Canberra, 2601, Australia.
Phone = +61 6 249 4625 (Office)   +61 6 251 5302 (Home)