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NAME | SYNOPSIS | DESCRIPTION | OPTIONS | COMMANDS | PARAMETER FORMATTING | EXAMPLES | SEE ALSO | NOTES | COLOPHON |
BUSCTL(1) busctl BUSCTL(1)
busctl - Introspect the bus
busctl [OPTIONS...] [COMMAND] [NAME...]
busctl may be used to introspect and monitor the D-Bus bus.
The following options are understood:
--address=ADDRESS
Connect to the bus specified by ADDRESS instead of using suitable
defaults for either the system or user bus (see --system and
--user options).
--show-machine
When showing the list of peers, show a column containing the
names of containers they belong to. See
systemd-machined.service(8).
--unique
When showing the list of peers, show only "unique" names (of the
form ":number.number").
--acquired
The opposite of --unique — only "well-known" names will be shown.
--activatable
When showing the list of peers, show only peers which have
actually not been activated yet, but may be started automatically
if accessed.
--match=MATCH
When showing messages being exchanged, show only the subset
matching MATCH. See sd_bus_add_match(3).
--size=
When used with the capture command, specifies the maximum bus
message size to capture ("snaplen"). Defaults to 4096 bytes.
--list
When used with the tree command, shows a flat list of object
paths instead of a tree.
--quiet
When used with the call command, suppresses display of the
response message payload. Note that even if this option is
specified, errors returned will still be printed and the tool
will indicate success or failure with the process exit code.
--verbose
When used with the call or get-property command, shows output in
a more verbose format.
--expect-reply=BOOL
When used with the call command, specifies whether busctl shall
wait for completion of the method call, output the returned
method response data, and return success or failure via the
process exit code. If this is set to "no", the method call will
be issued but no response is expected, the tool terminates
immediately, and thus no response can be shown, and no success or
failure is returned via the exit code. To only suppress output of
the reply message payload, use --quiet above. Defaults to "yes".
--auto-start=BOOL
When used with the call command, specifies whether the method
call should implicitly activate the called service, should it not
be running yet but is configured to be auto-started. Defaults to
"yes".
--allow-interactive-authorization=BOOL
When used with the call command, specifies whether the services
may enforce interactive authorization while executing the
operation, if the security policy is configured for this.
Defaults to "yes".
--timeout=SECS
When used with the call command, specifies the maximum time to
wait for method call completion. If no time unit is specified,
assumes seconds. The usual other units are understood, too (ms,
us, s, min, h, d, w, month, y). Note that this timeout does not
apply if --expect-reply=no is used, as the tool does not wait for
any reply message then. When not specified or when set to 0, the
default of "25s" is assumed.
--augment-creds=BOOL
Controls whether credential data reported by list or status shall
be augmented with data from /proc. When this is turned on, the
data shown is possibly inconsistent, as the data read from /proc
might be more recent than the rest of the credential information.
Defaults to "yes".
--user
Talk to the service manager of the calling user, rather than the
service manager of the system.
--system
Talk to the service manager of the system. This is the implied
default.
-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 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.
-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.
The following commands are understood:
list
Show all peers on the bus, by their service names. By default,
shows both unique and well-known names, but this may be changed
with the --unique and --acquired switches. This is the default
operation if no command is specified.
status [SERVICE]
Show process information and credentials of a bus service (if one
is specified by its unique or well-known name), a process (if one
is specified by its numeric PID), or the owner of the bus (if no
parameter is specified).
monitor [SERVICE...]
Dump messages being exchanged. If SERVICE is specified, show
messages to or from this peer, identified by its well-known or
unique name. Otherwise, show all messages on the bus. Use Ctrl-C
to terminate the dump.
capture [SERVICE...]
Similar to monitor but writes the output in pcap format (for
details, see the Libpcap File Format[1] description). Make sure
to redirect standard output to a file. Tools like wireshark(1)
may be used to dissect and view the resulting files.
tree [SERVICE...]
Shows an object tree of one or more services. If SERVICE is
specified, show object tree of the specified services only.
Otherwise, show all object trees of all services on the bus that
acquired at least one well-known name.
introspect SERVICE OBJECT [INTERFACE]
Show interfaces, methods, properties and signals of the specified
object (identified by its path) on the specified service. If the
interface argument is passed, the output is limited to members of
the specified interface.
call SERVICE OBJECT INTERFACE METHOD [SIGNATURE [ARGUMENT...]]
Invoke a method and show the response. Takes a service name,
object path, interface name and method name. If parameters shall
be passed to the method call, a signature string is required,
followed by the arguments, individually formatted as strings. For
details on the formatting used, see below. To suppress output of
the returned data, use the --quiet option.
get-property SERVICE OBJECT INTERFACE PROPERTY...
Retrieve the current value of one or more object properties.
Takes a service name, object path, interface name and property
name. Multiple properties may be specified at once, in which case
their values will be shown one after the other, separated by
newlines. The output is, by default, in terse format. Use
--verbose for a more elaborate output format.
set-property SERVICE OBJECT INTERFACE PROPERTY SIGNATURE ARGUMENT...
Set the current value of an object property. Takes a service
name, object path, interface name, property name, property
signature, followed by a list of parameters formatted as strings.
help
Show command syntax help.
The call and set-property commands take a signature string followed
by a list of parameters formatted as string (for details on D-Bus
signature strings, see the Type system chapter of the D-Bus
specification[2]). For simple types, each parameter following the
signature should simply be the parameter's value formatted as string.
Positive boolean values may be formatted as "true", "yes", "on", or
"1"; negative boolean values may be specified as "false", "no",
"off", or "0". For arrays, a numeric argument for the number of
entries followed by the entries shall be specified. For variants, the
signature of the contents shall be specified, followed by the
contents. For dictionaries and structs, the contents of them shall be
directly specified.
For example,
s jawoll
is the formatting of a single string "jawoll".
as 3 hello world foobar
is the formatting of a string array with three entries, "hello",
"world" and "foobar".
a{sv} 3 One s Eins Two u 2 Yes b true
is the formatting of a dictionary array that maps strings to
variants, consisting of three entries. The string "One" is assigned
the string "Eins". The string "Two" is assigned the 32-bit unsigned
integer 2. The string "Yes" is assigned a positive boolean.
Note that the call, get-property, introspect commands will also
generate output in this format for the returned data. Since this
format is sometimes too terse to be easily understood, the call and
get-property commands may generate a more verbose, multi-line output
when passed the --verbose option.
Example 1. Write and Read a Property
The following two commands first write a property and then read it
back. The property is found on the "/org/freedesktop/systemd1" object
of the "org.freedesktop.systemd1" service. The name of the property
is "LogLevel" on the "org.freedesktop.systemd1.Manager" interface.
The property contains a single string:
# busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
# busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
s "debug"
Example 2. Terse and Verbose Output
The following two commands read a property that contains an array of
strings, and first show it in terse format, followed by verbose
format:
$ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
$ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
ARRAY "s" {
STRING "LANG=en_US.UTF-8";
STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
};
Example 3. Invoking a Method
The following command invokes the "StartUnit" method on the
"org.freedesktop.systemd1.Manager" interface of the
"/org/freedesktop/systemd1" object of the "org.freedesktop.systemd1"
service, and passes it two strings "cups.service" and "replace". As a
result of the method call, a single object path parameter is received
and shown:
# busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"
o "/org/freedesktop/systemd1/job/42684"
dbus-daemon(1), D-Bus[3], sd-bus(3), systemd(1), machinectl(1),
wireshark(1)
1. Libpcap File Format
https://wiki.wireshark.org/Development/LibpcapFileFormat
2. Type system chapter of the D-Bus specification
http://dbus.freedesktop.org/doc/dbus-specification.html#type-system
3. D-Bus
https://www.freedesktop.org/wiki/Software/dbus
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2017-07-05. If you dis‐
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believe there is a better or more up-to-date source for the page, or
you have corrections or improvements to the information in this
COLOPHON (which is not part of the original manual page), send a mail
to man-pages@man7.org
systemd 234 BUSCTL(1)
Pages that refer to this page: sd-bus(3), systemd.directives(7), systemd.index(7)