How to Use systemctl Command in Linux: Syntax and Examples

Use the systemctl command to control system services on Linux. It manages services by starting, stopping, enabling, or checking their status with simple commands like systemctl start service or systemctl status service.

Syntax

The basic syntax of systemctl is:

• systemctl [command] [service_name]
• command is the action you want to perform, like start, stop, restart, status, or enable.
• service_name is the name of the service you want to manage, usually ending with .service.

bash

systemctl [command] [service_name]

Example

This example shows how to check the status of the ssh service, start it if it is stopped, and then enable it to start automatically on boot.

bash

systemctl status ssh.service
sudo systemctl start ssh.service
sudo systemctl enable ssh.service

Output

● ssh.service - OpenBSD Secure Shell server
   Loaded: loaded (/lib/systemd/system/ssh.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2024-06-14 10:00:00 UTC; 5min ago

Created symlink /etc/systemd/system/multi-user.target.wants/ssh.service → /lib/systemd/system/ssh.service.

Common Pitfalls

Common mistakes include:

• Forgetting to use sudo when running systemctl commands that change service states.
• Using incorrect service names or omitting the .service suffix when required.
• Trying to start a service that is masked or disabled without enabling it first.

Always check the service status before and after commands to confirm changes.

bash

sudo systemctl start apache2
# Wrong: missing sudo
systemctl start apache2
# Right: with sudo
sudo systemctl start apache2

Quick Reference

Command	Description
systemctl start [service]	Start a service immediately
systemctl stop [service]	Stop a running service
systemctl restart [service]	Restart a service
systemctl status [service]	Show current status of a service
systemctl enable [service]	Enable service to start at boot
systemctl disable [service]	Disable service from starting at boot
systemctl reload [service]	Reload service configuration without restarting
systemctl is-active [service]	Check if service is active
systemctl list-units --type=service	List all active services

Key Takeaways

Use systemctl with commands like start, stop, status, and enable to manage Linux services.

Always run systemctl commands with sudo when changing service states.

Check service status before and after to confirm your commands worked.

Use the exact service name, usually ending with .service.

Use systemctl list-units --type=service to see all active services.