To restart a Unix or Linux system, you can use the shutdown command with the -r option to reboot the system.
For example, to reboot the system immediately, you can use the following command:
sudo shutdown -r now
This will shutdown all processes and services, and then restart the system.
You can also specify a delay before the system is restarted by using the + followed by the number of minutes. For example, to reboot the system in 10 minutes, you can use the following command:
sudo shutdown -r +10
You can also specify a specific time to reboot the system by using the hh:mm format. For example, to reboot the system at 3:00 AM, you can use the following command:
sudo shutdown -r 03:00
It is important to note that the shutdown command requires superuser privileges to restart the system. Therefore, you may need to use the sudo command to run the shutdown command as the root user.
For more information about the shutdown command and its options, you can consult the documentation for your specific Unix or Linux system. You can also use the reboot command to restart the system on some systems.