loginctl - Control the systemd login manager
loginctl [OPTIONS...] {COMMAND} [NAME...]
The following commands are understood:
list-sessions
List current sessions.
session-status [ID...]
Show terse runtime status information about one or more
sessions, followed by the most recent log data from the journal. Takes one or
more session identifiers as parameters. If no session identifiers are passed,
the status of the caller's session is shown. This function is intended to
generate human-readable output. If you are looking for computer-parsable
output, use show-session instead.
show-session [ID...]
Show properties of one or more sessions or the manager
itself. If no argument is specified, properties of the manager will be shown.
If a session ID is specified, properties of the session are shown. By default,
empty properties are suppressed. Use --all to show those too. To select
specific properties to show, use --property=. This command is intended
to be used whenever computer-parsable output is required. Use
session-status if you are looking for formatted human-readable
output.
activate [ID]
Activate a session. This brings a session into the
foreground if another session is currently in the foreground on the respective
seat. Takes a session identifier as argument. If no argument is specified, the
session of the caller is put into foreground.
lock-session [ID...], unlock-session
[ID...]
Activates/deactivates the screen lock on one or more
sessions, if the session supports it. Takes one or more session identifiers as
arguments. If no argument is specified, the session of the caller is
locked/unlocked.
lock-sessions, unlock-sessions
Activates/deactivates the screen lock on all current
sessions supporting it.
terminate-session ID...
Terminates a session. This kills all processes of the
session and deallocates all resources attached to the session.
kill-session ID...
Send a signal to one or more processes of the session.
Use --kill-who= to select which process to kill. Use --signal=
to select the signal to send.
list-users
List currently logged in users.
user-status [USER...]
Show terse runtime status information about one or more
logged in users, followed by the most recent log data from the journal. Takes
one or more user names or numeric user IDs as parameters. If no parameters are
passed, the status is shown for the user of the session of the caller. This
function is intended to generate human-readable output. If you are looking for
computer-parsable output, use show-user instead.
show-user [USER...]
Show properties of one or more users or the manager
itself. If no argument is specified, properties of the manager will be shown.
If a user is specified, properties of the user are shown. By default, empty
properties are suppressed. Use --all to show those too. To select
specific properties to show, use --property=. This command is intended
to be used whenever computer-parsable output is required. Use
user-status if you are looking for formatted human-readable
output.
enable-linger [USER...], disable-linger
[USER...]
Enable/disable user lingering for one or more users. If
enabled for a specific user, a user manager is spawned for the user at boot
and kept around after logouts. This allows users who are not logged in to run
long-running services. Takes one or more user names or numeric UIDs as
argument. If no argument is specified, enables/disables lingering for the user
of the session of the caller.
See also KillUserProcesses= setting in
logind.conf(5).
terminate-user USER...
Terminates all sessions of a user. This kills all
processes of all sessions of the user and deallocates all runtime resources
attached to the user.
kill-user USER...
Send a signal to all processes of a user. Use
--signal= to select the signal to send.
list-seats
List currently available seats on the local system.
seat-status [NAME...]
Show terse runtime status information about one or more
seats. Takes one or more seat names as parameters. If no seat names are passed
the status of the caller's session's seat is shown. This function is intended
to generate human-readable output. If you are looking for computer-parsable
output, use show-seat instead.
show-seat [NAME...]
Show properties of one or more seats or the manager
itself. If no argument is specified, properties of the manager will be shown.
If a seat is specified, properties of the seat are shown. By default, empty
properties are suppressed. Use --all to show those too. To select
specific properties to show, use --property=. This command is intended
to be used whenever computer-parsable output is required. Use
seat-status if you are looking for formatted human-readable
output.
attach NAME DEVICE...
Persistently attach one or more devices to a seat. The
devices should be specified via device paths in the /sys/ file system. To
create a new seat, attach at least one graphics card to a previously unused
seat name. Seat names may consist only of a–z, A–Z, 0–9,
"-" and "_" and must be prefixed with "seat". To
drop assignment of a device to a specific seat, just reassign it to a
different seat, or use flush-devices.
flush-devices
Removes all device assignments previously created with
attach. After this call, only automatically generated seats will
remain, and all seat hardware is assigned to them.
terminate-seat NAME...
Terminates all sessions on a seat. This kills all
processes of all sessions on the seat and deallocates all runtime resources
attached to them.
The following options are understood:
--no-ask-password
Do not query the user for authentication for privileged
operations.
-p, --property=
When showing session/user/seat properties, limit display
to certain properties as specified as argument. If not specified, all set
properties are shown. The argument should be a property name, such as
"Sessions". If specified more than once, all properties with the
specified names are shown.
--value
When showing session/user/seat properties, only print the
value, and skip the property name and "=".
-a, --all
When showing session/user/seat properties, show all
properties regardless of whether they are set or not.
-l, --full
Do not ellipsize process tree entries.
--kill-who=
When used with kill-session, choose which
processes to kill. Must be one of leader, or all to select
whether to kill only the leader process of the session or all processes of the
session. If omitted, defaults to all.
-s, --signal=
When used with kill-session or kill-user,
choose which signal to send to selected processes. Must be one of the well
known signal specifiers, such as SIGTERM, SIGINT or
SIGSTOP. If omitted, defaults to SIGTERM.
-n, --lines=
When used with user-status and
session-status, controls the number of journal lines to show, counting
from the most recent ones. Takes a positive integer argument. Defaults to
10.
-o, --output=
When used with
user-status and
session-status, controls the formatting of the journal entries that are
shown. For the available choices, see
journalctl(1). Defaults to
"short".
-H, --host=
Execute the operation remotely. Specify a hostname, or a
username and hostname separated by "@", to connect to. The hostname
may optionally be suffixed by a port ssh is listening on, separated by
":", and then a container name, separated by "/", which
connects directly to a specific container on the specified host. This will use
SSH to talk to the remote machine manager instance. Container names may be
enumerated with machinectl -H HOST. Put IPv6 addresses in
brackets.
-M, --machine=
Execute operation on a local container. Specify a
container name to connect to.
--no-pager
Do not pipe output into a pager.
--no-legend
Do not print the legend, i.e. column headers and the
footer with hints.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
On success, 0 is returned, a non-zero failure code otherwise.
Example 1. Querying user status
$ loginctl user-status
fatima (1005)
Since: Sat 2016-04-09 14:23:31 EDT; 54min ago
State: active
Sessions: 5 *3
Unit: user-1005.slice
├─user@1005.service
...
├─session-3.scope
...
└─session-5.scope
├─3473 login -- fatima
└─3515 -zsh
Apr 09 14:40:30 laptop login[2325]: pam_unix(login:session):
session opened for user fatima by LOGIN(uid=0)
Apr 09 14:40:30 laptop login[2325]: LOGIN ON tty3 BY fatima
There are two sessions, 3 and 5. Session 3 is a graphical session,
marked with a star. The tree of processing including the two corresponding
scope units and the user manager unit are shown.
$SYSTEMD_PAGER
Pager to use when
--no-pager is not given;
overrides
$PAGER. If neither
$SYSTEMD_PAGER nor
$PAGER
are set, a set of well-known pager implementations are tried in turn,
including
less(1) and
more(1), until one is found. If no pager
implementation is discovered no pager is invoked. Setting this environment
variable to an empty string or the value "cat" is equivalent to
passing
--no-pager.
$SYSTEMD_LESS
Override the options passed to
less (by default
"FRSXMK").
Users might want to change two options in particular:
K
This option instructs the pager to exit immediately when
Ctrl+C is pressed. To allow
less to handle Ctrl+C itself to switch back
to the pager command prompt, unset this option.
If the value of $SYSTEMD_LESS does not include
"K", and the pager that is invoked is less, Ctrl+C will be
ignored by the executable, and needs to be handled by the pager.
X
This option instructs the pager to not send termcap
initialization and deinitialization strings to the terminal. It is set by
default to allow command output to remain visible in the terminal even after
the pager exits. Nevertheless, this prevents some pager functionality from
working, in particular paged output cannot be scrolled with the mouse.
See less(1) for more discussion.
$SYSTEMD_LESSCHARSET
Override the charset passed to less (by default
"utf-8", if the invoking terminal is determined to be UTF-8
compatible).
$SYSTEMD_PAGERSECURE
Takes a boolean argument. When true, the
"secure" mode of the pager is enabled; if false, disabled. If
$SYSTEMD_PAGERSECURE is not set at all, secure mode is enabled if the
effective UID is not the same as the owner of the login session, see
geteuid(2) and
sd_pid_get_owner_uid(3). In secure mode,
LESSSECURE=1 will be set when invoking the pager, and the pager shall
disable commands that open or create new files or start new subprocesses. When
$SYSTEMD_PAGERSECURE is not set at all, pagers which are not known to
implement secure mode will not be used. (Currently only
less(1)
implements secure mode.)
Note: when commands are invoked with elevated privileges, for
example under sudo(8) or pkexec(1), care must be taken to
ensure that unintended interactive features are not enabled.
"Secure" mode for the pager may be enabled automatically as
describe above. Setting SYSTEMD_PAGERSECURE=0 or not removing it from
the inherited environment allows the user to invoke arbitrary commands. Note
that if the $SYSTEMD_PAGER or $PAGER variables are to be
honoured, $SYSTEMD_PAGERSECURE must be set too. It might be
reasonable to completely disable the pager using --no-pager
instead.
$SYSTEMD_COLORS
The value must be a boolean. Controls whether colorized
output should be generated. This can be specified to override the decision
that systemd makes based on $TERM and what the console is
connected to.
$SYSTEMD_URLIFY
The value must be a boolean. Controls whether clickable
links should be generated in the output for terminal emulators supporting
this. This can be specified to override the decision that systemd makes
based on $TERM and other conditions.