:PROPERTIES:
:ID:       80866258-4fd5-4ddc-b3e4-00fa3d3372d3
:END:
#+title: Command line: systemctl
#+date: 2021-07-27 13:47:34 +08:00
#+date_modified: 2022-12-06 18:25:19 +08:00
#+language: en
#+property: header_args  :eval no


The go-to command to manage units in a systemd-ful system.

For full details, you can view the =systemctl.1= manual page.




* Synopsis

#+begin_src shell
systemctl [OPTIONS...] COMMAND [COMMAND_ARGS...] [COMMAND_OPTIONS...]
#+end_src




* Options

- =--user= runs the binary in user mode with the user-specific options and load-path.
  See [[id:c7edff80-6dea-47fc-8ecd-e43b5ab8fb1e][systemd at user-level]] for more details.

- =--help= is an obvious one.
  It prints a detailed help section of the command.

- =--host= controls a remote system.
  Meaning, you can manage services and timers remotely.
  Will not work on certain subcommands such as =edit=.

- =--container= is similar to =--host= but operates on a local container.

- =--with-dependencies= will show the output of the unit specified along with its dependencies.
  This is only effective on certain subcommands such as =status=, =list-units=, =cat=, and =list-unit-files=.

- =-p PROPERTIES= shows only the listed properties.
  Very useful for filtering the properties for =systemctl show= subcommand.
  Take note =PROPERTIES= can be a list of properties to show delimited with a comma.

- =-P PROPERTIES= shows the value of the listed properies.
  Similar to =-p=, =PROPERTIES= can be a comma-delimited list of properties to be shown.




* Subcommands

- =show PATTERN= shows the properties of the matched units.
  It can also show with multiple units with a helpful label and proper formatting (which is very nice).
  This is the go-to subcommand for debugging a service.

- =enable UNIT= and =disable UNIT= enables and disables units.
  It mainly adds the unit activation at startup.

  + =--now= starts/stops the unit.
    It is the equivalent of =systemctl {enable,disable} UNIT && systemctl {start,stop} UNIT=.
    Pretty handy if you intend to add the unit at startup and want to use it now.

- =start UNIT= and =stop UNIT= starts and stops the unit, respectively.
  Though, this doesn't activate

- =restart UNIT= restarts the given unit.
  This also reloads with the modified changes of the unit.

- In some cases where restarting the unit isn't enough, =daemon-reload= will reload the daemon with the modified units.
  systemd does not have reload-at-change for its unit.
  That is, if a unit is modified, systemd will not run the modified version until reloaded.

- =show-environment= shows the environment variables of the system.

- =list-units [PATTERN...]= is self-explanatory ;p.

- =is-active PATTERN...= prints the status of the matched unit and exits successfully if it's active.

- =cat PATTERN...= shows contents of the given units in a neat formatted page.