As a Linux administrator or operator, you need to use the "shutdown" command in order to shutdown the Linux system securely and safely.

In this tutorial, you will learn how to use the "shutdown" command to shutdown the system with different options. We will walkthrough the "shutdown" command with detailed explantions and examples.

The Shutdown Command Syntax

Before going into the detail "shutdown" command explanation, we want to show you the basic syntax of the Linux shutdown command is as follows:



[options] - define the shutdown shutdown optiosn such as: halt, power-off, or reboot the server.
[time] - this argument specifies when you want the shutdown to perform.
[message] - this argument will add a message that announces the shutdown to all the users.

The Standard Shutdown Command

The simplest standard way to shutdown the system is to use the "shutdown" command with no argument.



With no argument specified in the shutdown command, the shutdown process will be started after 1 minute, which is the default shutdown time interval.

How to Shut Down the system immediately

In the previous command, if you issue the shutdown command without parameter, you would need to wait for 1 minute after the command. However, in some cases, you need to shutdown the system immediately. In that case, you can use the following command

How to Shut Down the system at a specified time

Alternatively, you can schedule a shutdown activity. To shutdown the system at the specific time, you need to pass the time argument after the "shutdown" command. The time parameter would be in absolute time format

For example, to schedule the system to shutdown at 9 A.M., the command is:





Besides, you may also use the relative time format in minutes(+m) to schedule the shutdown after (m) minutes that you have issued the command:

For example, to schedule the system to shutdown at after 30 minutes:

How to Broadcast a Custom Message for System Shut Down

As the system administrator, if you want to schedule a shutdown activity and want to notified all the users within the system, you can add a custom message in the shutdown schedule to inform the users that the system will be shutdown at specific time. The command of doing that is:



For example, you would like to schedule the system for emergency shutdown in 30 minutes, and you want to inform all the users. You can use the following command:

How to Cancel a Scheduled System Shut Down

In some cases, you need to cancel a scheduled system shutdown event. To cancel a sheduled shutdown, you may use the followimg command:

Conclusion

This tutorial shared the basic "shutdown" command in the Linux environment. As a Linux administrator, you are unavoidable to use the shutdown command for system maintenance and other activities. Normally, you should have a well planned schedule for all kind of shutdown activities.