Tom Widland writes:
 > Is there an introspective way to get the ip address of the computer
 > running my ACL program, in either Unix or Windows?
 > 
 > Thanks
 > 

This works under ACL/Linux:

USER(1): (defconstant +ifconfig+ "/sbin/ifconfig -a")
+IFCONFIG+

;;; change this string to whatever works on your Unix variant.
;;; there are Unixen about that won't even let you do this without
;;; being root

USER(11): (defun get-ip-address ()
	   (with-open-stream (stream (excl:run-shell-command +ifconfig+ :wait nil :output :stream))
	     (loop for line = (read-line stream nil nil)
	           while line
		   do
		     (format t "~A" line))))
GET-IP-ADDRESS

Note that you would have to parse the output instead of just
displaying it like I did. Also this will potentially give you heaps of 
interfaces since you can easily have lo (loopback for 127.0.0.1), some 
token ring interfaces, some ethernet interfaces, some slip and/or ppp
connections and some aliases if you're doing NAT. The concept of *the* 
IP address of a machine is ill defined.

Lieven