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halt – Shut down a running Linux operating system

The halt command is used to shut down a running Linux operating system. It is a simple command that initiates the system shutdown process.

Overview

The halt command is used to initiate a system shutdown. When executed, it sends a signal to all running processes to terminate them and then halts the system. The shutdown process is initiated in a safe and controlled manner, allowing the system to save any unsaved data and close all open files.

Syntax

The basic syntax of the halt command is:

halt [OPTIONS]

Examples

To shut down the system immediately, simply execute the halt command with no options:

$ halt

This will immediately initiate the system shutdown process.

If you want to delay the shutdown process by a specific amount of time, you can use the -t option followed by the number of seconds to delay:

$ halt -t 60

This will initiate the shutdown process after a delay of 60 seconds.

Options

The following table lists all available options for the halt command:

Option Description
-f, --force Forces an immediate shutdown, without saving unsaved data or closing open files.
-p, --poweroff Shuts down the system and turns off power.
-w, --wtmp-only Does not actually halt the system, but only writes the shutdown message to the wtmp log file.
-d, --no-wtmp Does not write the shutdown message to the wtmp log file.

Troubleshooting Tips

  • If the halt command does not work, try using the shutdown command with the -h option instead.
  • If the system does not shut down properly, try using the reboot command to restart the system and then try shutting it down again.

Notes

  • The halt command requires root privileges to execute.
  • The -f option should be used with caution, as it can cause data loss and file corruption.

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