[SPARCbook] SB3 and short reads

[Nickolai Zeldovich]

> This equates to a shutdown that avoids the confirmation question, waits 0
> seconds (grace = 0) and goes down to runlevel 0.

It might be worth noting that /usr/sbin/shutdown, a shell script, actually
waits 30 seconds if you say -g0, so I usually use -g1 to make it shut down
faster. (Or you could just edit the shutdown shell script to change this.)

-- kolya