exit Terminates the shell.
halt Stop the system.
init Process control initialization.
initscript Script that executes inittab commands.
logout Log the user off the system.
poweroff Brings the system down.
reboot Reboot the system.
runlevel List the current and previous runlevel.
setsid Run a program in a new session.
shutdown If your system has many users, use the command "shutdown -h +time message", where time is the time in minutes until the system is halted, and message is a short explanation of why the system is shutting down.
# shutdown -h +10 'We will install a new disk. System should be back on-line in three
hours.'
telinit By requesting run level 1 a system can be taken to single user mode.