If you have multiple mac os x machines on a LAN, you can run
rwhod found at
/usr/sbin/rwhod; you will have to launch it with "sudo rwhod". If you run this on all machines on your LAN you can type
ruptime and get the uptime of those machines:
[:/var/rwho] bryan% ruptime
www100 up 3+01:53, 1 user, load 1.12, 1.03, 1.01
www200 up 8+04:30, 1 user, load 1.99, 1.99, 1.99
[
Editor's note: I could not get this to work on my machines; ruptime returns a "no hosts in /var/rwho" error message. Also, in trying to investigate why I was getting this message, I read a couple of articles that indicate that rwhod can flood a network with informational messages. These articles recommended disabling rwhod to improve network performance. Any thoughts on why I couldn't make this work, and/or on rwhod in general?]