| LOGINCTL(1) | loginctl | LOGINCTL(1) |
.SH "NAME" loginctl - Control the systemd login manager
.SH "SYNOPSIS"
.HP 216u
loginctl
[OPTIONS...]
{COMMAND}
[NAME...]
.SH "DESCRIPTION"
.PP loginctl may be used to introspect and control the state of the
systemd(1) login manager systemd-logind.service(8).
.SH "COMMANDS"
.PP The following commands are understood:
.SS "Session Commands"
.PP list-sessions
List current sessions. The JSON format output can be toggled using
--json= or -j option.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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. Specially, if the given ID
is self, the session to which the loginctl process belongs is used.
If auto, the current session is used as with self if exists, and falls back
to the current user's graphical session. 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.
Added in version 233.
.RE
.PP 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.
Added in version 219.
.RE
.PP 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.
Added in version 233.
.RE
.PP lock-sessions, unlock-sessions
Activates/deactivates the screen lock on all current sessions supporting
it.
Added in version 188.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.SS "User Commands"
.PP list-users
List currently logged in users. The JSON format output can be toggled using
--json= or -j option.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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).
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.SS "Seat Commands"
.PP list-seats
List currently available seats on the local system. The JSON format output
can be toggled using --json= or -j option.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
Added in version 233.
.RE
.PP 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.
.RE
.PP 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.
Added in version 233.
.RE
.SH "OPTIONS"
.PP The following options are understood:
.PP -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.
.RE
.PP --value
When showing session/user/seat properties, only print the value, and skip the
property name and =.
Added in version 230.
.RE
.PP -a, --all
When showing session/user/seat properties, show all properties regardless of
whether they are set or not.
.RE
.PP -l, --full
Do not ellipsize process tree entries.
Added in version 198.
.RE
.PP --kill-whom=
When used with kill-session, choose which processes to kill. Takes 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.
Added in version 252.
.RE
.PP -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.
.RE
.PP -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.
Added in version 219.
.RE
.PP -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.
Added in version 219.
.RE
.PP -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.
.RE
.PP -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.
.RE
.PP --no-ask-password
Do not query the user for authentication for privileged operations.
.RE
.PP --no-pager
Do not pipe output into a pager.
.RE
.PP --no-legend
Do not print the legend, i.e. column headers and the footer with hints.
.RE
.PP --json=MODE
Shows output formatted as JSON. Expects one of short (for the shortest
possible output without any redundant whitespace or line breaks), pretty
(for a pretty version of the same, with indentation and line breaks) or off
(to turn off JSON output, the default).
.RE
.PP -j
Equivalent to --json=pretty if running on a terminal, and
--json=short otherwise.
.RE
.PP -h, --help
Print a short help text and exit.
.RE
.PP --version
Print a short version string and exit.
.RE
.SH "EXIT STATUS"
.PP On success, 0 is returned, a non-zero failure code otherwise.
.SH "EXAMPLES"
.PP 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
.PP 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.
.SH "ENVIRONMENT"
.PP $SYSTEMD_LOG_LEVEL
The maximum log level of emitted messages (messages with a higher log level,
i.e. less important ones, will be suppressed). Takes a comma-separated list
of values. A value may be 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. Each value may optionally be
prefixed with one of console, syslog, kmsg or
journal followed by a colon to set the maximum log level for that
specific log target (e.g. SYSTEMD_LOG_LEVEL=debug,console:info
specifies to log at debug level except when logging to the console which
should be at info level). Note that the global maximum log level takes
priority over any per target maximum log levels.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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.
.RE
.PP $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).
.RE
.PP $SYSTEMD_LOG_RATELIMIT_KMSG
Whether to ratelimit kmsg or not. Takes a boolean. Defaults to true. If
disabled, systemd will not ratelimit messages written to kmsg.
.RE
.PP $SYSTEMD_PAGER, $PAGER
Pager to use when --no-pager is not given. $SYSTEMD_PAGER is
used if set; otherwise $PAGER is used. If neither
$SYSTEMD_PAGER nor $PAGER are set, a set of well-known pager
implementations is tried in turn, including less(1) and
more(1), until one is found. If no pager implementation is
discovered, no pager is invoked. Setting those environment variables to an
empty string or the value cat is equivalent to passing
--no-pager.
Note: if $SYSTEMD_PAGERSECURE is not set, $SYSTEMD_PAGER and
$PAGER can only be used to disable the pager (with cat or ), and are
otherwise ignored.
.RE
.PP $SYSTEMD_LESS
Override the options passed to less (by default FRSXMK).
Users might want to change two options in particular:
.PP 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.
.RE
.PP 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.
.RE
.sp
Note that setting the regular $LESS environment variable has no effect
for less invocations by systemd tools.
See less(1) for more discussion.
.RE
.PP $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.
.RE
.PP $SYSTEMD_PAGERSECURE
Common pager commands like less(1), in addition to "paging",
i.e. scrolling through the output, support opening of or writing to other
files and running arbitrary shell commands. When commands are invoked with
elevated privileges, for example under sudo(8) or pkexec(1),
the pager becomes a security boundary. Care must be taken that only programs
with strictly limited functionality are used as pagers, and unintended
interactive features like opening or creation of new files or starting of
subprocesses are not allowed. "Secure mode" for the pager may be
enabled as described below, if the pager supports that (most pagers
are not written in a way that takes this into consideration). It is
recommended to either explicitly enable "secure mode" or to
completely disable the pager using --no-pager or PAGER=cat
when allowing untrusted users to execute commands with elevated
privileges.
This option takes a boolean argument. When set to true, the "secure
mode" of the pager is enabled. In "secure mode",
LESSSECURE=1 will be set when invoking the pager, which instructs the
pager to disable commands that open or create new files or start new
subprocesses. Currently only less(1) is known to understand this
variable and implement "secure mode".
When set to false, no limitation is placed on the pager. Setting
SYSTEMD_PAGERSECURE=0 or not removing it from the inherited
environment may allow the user to invoke arbitrary commands.
When $SYSTEMD_PAGERSECURE is not set, systemd tools attempt to
automatically figure out if "secure mode" should be enabled and
whether the pager supports it. "Secure mode" is enabled if the
effective UID is not the same as the owner of the login session, see
geteuid(2) and sd_pid_get_owner_uid(3), or when running under
sudo(8) or similar tools ($SUDO_UID is set [1]). In those
cases, SYSTEMD_PAGERSECURE=1 will be set and pagers which are not
known to implement "secure mode" will not be used at all. Note
that this autodetection only covers the most common mechanisms to elevate
privileges and is intended as convenience. It is recommended to explicitly
set $SYSTEMD_PAGERSECURE or disable the pager.
Note that if the $SYSTEMD_PAGER or $PAGER variables are to be
honoured, other than to disable the pager, $SYSTEMD_PAGERSECURE must
be set too.
.RE
.PP $SYSTEMD_COLORS
Takes a boolean argument, or a special value. By default (unset),
systemd and related utilities will use colors in their output if
possible. If $COLORTERM is set to truecolor or 24bit, 24-bit colors
will be enabled, 256 colors otherwise, unless $NO_COLOR or
$TERM indicates colors are disabled.
.PP true
Same as unset, except that $NO_COLOR is ignored.
.RE
.PP false
The output will be monochrome.
.RE
.PP 16, 256, 24bit
Always use the base 16 ANSI colors, 256 colors, or 24 bit color,
respectively.
.RE
.PP auto-16, auto-256, auto-24bit
Use the given quantity of colours, subject to $TERM, and what the
console is connected to.
.RE
.sp
.RE
.PP $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.
.RE
.SH "SEE ALSO"
.PP systemd(1), systemctl(1), systemd-logind.service(8),
logind.conf(5)
NOTES
- 1.
-
It is recommended for other tools to set and check $SUDO_UID as appropriate, treating it is a common interface.
| systemd 262.2 |