systemctl is a command-line utility in Linux systems that is used to control and manage the systemd system and service manager. Systemd is a system initialization and management daemon that provides a range of features for controlling the startup, management, and monitoring of processes and services on a Linux system.
Here are some key functionalities and practical examples of using the systemctl command:
- Managing System Services:
- Start a service:
systemctl start service_name
Stop a service:
systemctl stop service_name
Restart a service:
systemctl restart service_name
Enable a service to start automatically on boot:
systemctl enable service_name
Disable a service from starting automatically on boot:
systemctl disable service_name
Check the status of a service:
systemctl status service_name
2. Managing the System:
- Reboot the system:
systemctl reboot
Shut down the system:
systemctl poweroff
Hibernate the system:
systemctl hibernate
Suspend the system:
systemctl suspend
3. Working with System Targets: System targets are groups of services and other units that define the system state. Common targets include graphical.target for the graphical desktop environment and multi-user.target for the command-line interface.
- Change the system target:
systemctl isolate target_name
4. Analyzing Logs:
- View the system log messages:
systemctl status
View the journal logs:
journalctl
5. Managing System Timers: Systemd provides a timer functionality that allows you to schedule and manage periodic tasks.
- Start a timer:
systemctl start timer_name
Stop a timer:
systemctl stop timer_name
Check the status of a timer:
systemctl status timer_name
These are just a few examples of the systemctl command’s functionalities. It provides a comprehensive interface for managing system services, targets, timers, and more. You can explore further options and features by referring to the systemctl manual page using the command man systemctl.