Which command is typically used to check available services and their status in a Linux system?

The command that is typically used to check available services and their status in a Linux system is "systemctl list-units." This command is a part of the systemd system and service manager, which is widely used in modern Linux distributions. It provides a comprehensive overview of all the units that are currently loaded into memory, showing both active (running) and inactive (stopped) services, along with their respective states.

"systemctl" is a versatile command that allows users to manage system services, including starting, stopping, and enabling services. The "list-units" option specifically targets units, which can include services, sockets, devices, and more. This command gives a clear view of services that are running, along with additional information about their status, such as whether they are enabled to start at boot.

In contrast, the other options do not correspond to standard commands in Linux for checking services. They do not exist in standard Linux distributions or do not follow common command syntax, which tends to invoke commands that start with "systemctl" for managing services. Thus, the use of "systemctl list-units" effectively covers the need to assess both the availability and status of services in a Linux environment.