[K12OSN] a script for killing all users

[Tom Wolfe]

In the past I've seen discussions on killing all users. I adapted the 
script killer.sh as follows and it seems to work well. I replaced the "who 
-u" with "ps aux" because it seems sometimes some users aren't in the who 
-u list. I run it at night to keep things clean.

Comments would be welcome. Also, if anyone has a script to kill idle user 
sessions that would be great -- that's next on my to do list.

### This defines USERS using the ps command
USERS=`ps aux | cut -f1 -d ' ' | sort -u`
### I don't want local machine accounts to be killed,
### just my Active Directory domain ones. The funny USER
### addition is to remove the first line of the ps command
NO_TOUCH_USERS=`cat /etc/passwd | cut -f1 -d ':'`\ USER

for user in $USERS; do
         echo $user
         GO=1
         for no_user in $NO_TOUCH_USERS; do
                 if [ $no_user = $user ]; then
#                       echo NOT killing $user
                         GO=0
                 fi
         done

         if [ $GO = 1 ]; then
#               echo killing $user
                 skill -KILL -u $user
                 sleep 1
                 skill -KILL -u $user
         fi
done