init

# Shutdown
init 0

# Reboot and bring back in single user mode
init 1

# Just reboot
init 6

System Run Level

• 6 run levels

• Run level 0: Shut down (or halt the system)

• Run level 1: Single-user mode; usually aliased as s or S
• Run level 2: Multiuser mode without networking
• Run level 3: Multiuser mode with networking (without GUI)
• Run level 5: Multiuser mode with networking (with GUI)

• Run level 6: Reboot the system

• 0, 1 and 6 are the main run levels

• 4 run level is undefined