By default, some important system services are started automatically when the system boots. For instance, the NetworkManager and Firewalld services will be automatically started at system boot. The startup services are also known as daemons in Linux and Unix-like operating systems. They will keep running in the background and do their job without any user intervention. In addition to the system services, some other third-party applications will also add themselves to the startup. In this brief guide, let us see how to find and list startup services at boot time in Linux and Unix-like systems.
Finding the list of startup services will differ depending upon the init system. Systemd is the default init system for the major newer versions of Linux distributions.
As stated above, this command shows the list of all services (both enabled and disabled at system boot) in your Linux system. You can verify it by looking under the STATE section in the above output. The services that are started at boot are marked as enabled, and the services that are not started are marked as disabled.