LOGINCTL(1) loginctl LOGINCTL(1)
NAME
loginctl - Control the systemd login manager
SYNOPSIS
loginctl [OPTIONS...] {COMMAND} [NAME...]
DESCRIPTION
loginctl may be used to introspect and control the state of the
systemd(1) login manager systemd-logind.service(8).
COMMANDS
The following commands are understood:
Session Commands
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. If the argument
is specified as empty string the session invoking the command is
terminated.
kill-session ID...
Send a signal to one or more processes of the session. Use
--kill-whom= to select which process to kill. Use --signal= to
select the signal to send. If the argument is specified as empty
string the signal is sent to the session invoking the command.
User Commands
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. If the argument is specified as empty string the
sessions of the user invoking the command are terminated.
kill-user USER...
Send a signal to all processes of a user. Use --signal= to select
the signal to send. If the argument is specified as empty string
the signal is sent to the sessions of the user invoking the
command.
Seat Commands
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.
OPTIONS
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-whom=
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.
The special value "help" will list the known values and the program
will exit immediately, and the special value "list" will list known
values along with the numerical signal numbers and the program will
exit immediately.
-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, optionally prefixed by a user name to connect as and a
separating "@" character. If the special string ".host" is used in
place of the container name, a connection to the local system is
made (which is useful to connect to a specific user's user bus:
"--user --machine=lennart@.host"). If the "@" syntax is not used,
the connection is made as root user. If the "@" syntax is used
either the left hand side or the right hand side may be omitted
(but not both) in which case the local user name and ".host" are
implied.
--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.
EXIT STATUS
On success, 0 is returned, a non-zero failure code otherwise.
EXAMPLES
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.
ENVIRONMENT
$SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a higher
log level, i.e. less important ones, will be suppressed). Either
one of (in order of decreasing importance) emerg, alert, crit, err,
warning, notice, info, debug, or an integer in the range 0...7. See
syslog(3) for more information.
$SYSTEMD_LOG_COLOR
A boolean. If true, messages written to the tty will be colored
according to priority.
This setting is only useful when messages are written directly to
the terminal, because journalctl(1) and other tools that display
logs will color messages based on the log level on their own.
$SYSTEMD_LOG_TIME
A boolean. If true, console log messages will be prefixed with a
timestamp.
This setting is only useful when messages are written directly to
the terminal or a file, because journalctl(1) and other tools that
display logs will attach timestamps based on the entry metadata on
their own.
$SYSTEMD_LOG_LOCATION
A boolean. If true, messages will be prefixed with a filename and
line number in the source code where the message originates.
Note that the log location is often attached as metadata to journal
entries anyway. Including it directly in the message text can
nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TID
A boolean. If true, messages will be prefixed with the current
numerical thread ID (TID).
Note that the this information is attached as metadata to journal
entries anyway. Including it directly in the message text can
nevertheless be convenient when debugging programs.
$SYSTEMD_LOG_TARGET
The destination for log messages. One of console (log to the
attached tty), console-prefixed (log to the attached tty but with
prefixes encoding the log level and "facility", see syslog(3), kmsg
(log to the kernel circular log buffer), journal (log to the
journal), journal-or-kmsg (log to the journal if available, and to
kmsg otherwise), auto (determine the appropriate log target
automatically, the default), null (disable log output).
$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.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER (as well
as $PAGER) will be silently ignored.
$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.
Note that setting the regular $LESS environment variable has no
effect for less invocations by systemd tools.
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).
Note that setting the regular $LESSCHARSET environment variable has
no effect for less invocations by systemd tools.
$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
Takes a boolean argument. When true, systemd and related utilities
will use colors in their output, otherwise the output will be
monochrome. Additionally, the variable can take one of the
following special values: "16", "256" to restrict the use of colors
to the base 16 or 256 ANSI colors, respectively. This can be
specified to override the automatic decision 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.
SEE ALSO
systemd(1), systemctl(1), systemd-logind.service(8), logind.conf(5)
systemd 252 LOGINCTL(1)
Generated by dwww version 1.15 on Sun Jun 2 01:56:24 CEST 2024.