Master Linux Shutdown: Safely Power Off or Reboot Your System

shutdown: Power Off or Reboot a Linux System

Function Description

The shutdown command safely powers off or reboots a Linux system. Before shutting down, it broadcasts a warning to all logged‑in users and freezes the login process, preventing new logins. It can shut down immediately, after a delay, or schedule a reboot.

Time Specification

The command accepts a time argument that can be an exact time (hh:mm) or a delay expressed as “+minutes”.

Command Syntax

shutdown [options] [parameter]

Option Meanings

-h : Shut down the system

-r : Reboot the system

-c : Cancel a pending shutdown

-n : Do not invoke init; let shutdown handle it

-k : Send warning messages only, do not actually shut down

-t <seconds> : Delay between warning and shutdown

-f : Do not run fsck on reboot

-F : Run fsck on reboot

Examples

Example 1 – Immediate shutdown

# shutdown -h now

Example 2 – Shutdown after 15 minutes with a message

# shutdown +5 "System will shutdown after 15 minutes"

Example 3 – Cancel a scheduled shutdown

# shutdown -c

Example 4 – Immediate reboot

# shutdown -r now

Example 5 – Reboot at a specific time (05:50)

# shutdown -r 05:50