How do you list services with systemctl?

systemctl --type=service lists services; add --all to include inactive ones, or list-unit-files to see which are enabled at boot.

A bare systemctl lists every active unit. To focus on services and control what's shown, you narrow with flags:

Note the difference between the two listings: list-units shows units that are loaded right now; list-unit-files shows what's installed on disk and whether it's enabled/disabled at boot — a service can be installed and enabled but not currently running.

The three status columns are the key to reading the output:

UNIT          LOAD   ACTIVE   SUB     DESCRIPTION
sshd.service  loaded active   running OpenSSH server
cups.service  loaded inactive dead    CUPS Printing

• LOAD — was the unit file read successfully? (loaded / not-found / error)
• ACTIVE — the high-level state systemd cares about (active / inactive / failed)
• SUB — the type-specific detail (running, exited, dead, listening…)

Filter by state to cut to the chase:

systemctl list-units --state=running
systemctl list-units --state=failed   # what's broken right now