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BUSCTL(1) | busctl | BUSCTL(1) |
NAME¶
busctl - Introspect the busSYNOPSIS¶
busctl [OPTIONS...] [COMMAND] [NAME...]
DESCRIPTION¶
busctl may be used to introspect and monitor the D-Bus bus.OPTIONS¶
The following options are understood: --address=ADDRESSConnect 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.
--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.
COMMANDS¶
The following commands are understood: listShow 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 the output to STDOUT to a file. Tools like
wireshark(1) may be used to dissect and view the generated 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.
PARAMETER FORMATTING¶
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
as 3 hello world foobar
a{sv} 3 One s Eins Two u 2 Yes b true
EXAMPLES¶
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"
$ 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"; };
# busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace" o "/org/freedesktop/systemd1/job/42684"
SEE ALSO¶
dbus-daemon(1), D-Bus[3], sd-bus(3), systemd(1), machinectl(1), wireshark(1)NOTES¶
- 1.
- Libpcap File Format
- 2.
- Type system chapter of the D-Bus specification
- 3.
- D-Bus
systemd 230 |