NAME¶

busctl - Introspect the bus

SYNOPSIS¶

busctl [OPTIONS...] [COMMAND] [NAME...]

DESCRIPTION¶

busctl may be used to introspect and monitor the D-Bus bus.

COMMANDS¶

The following commands are understood:

list

status [SERVICE]

monitor [SERVICE...]

capture [SERVICE...]

tree [SERVICE...]

introspect SERVICE OBJECT [INTERFACE]

call SERVICE OBJECT INTERFACE METHOD [SIGNATURE [ARGUMENT...]]

emit OBJECT INTERFACE SIGNAL [SIGNATURE [ARGUMENT...]]

wait [SERVICE] OBJECT INTERFACE SIGNAL

get-property SERVICE OBJECT INTERFACE PROPERTY...

set-property SERVICE OBJECT INTERFACE PROPERTY SIGNATURE ARGUMENT...

help

OPTIONS¶

The following options are understood:

--address=ADDRESS

--show-machine

--unique

--acquired

--activatable

--match=MATCH

--size=

--list

-q, --quiet

--verbose

--xml-interface

--json=MODE

-j

--expect-reply=BOOL

--auto-start=BOOL

--allow-interactive-authorization=BOOL

--timeout=SECS

--limit-messages=NUMBER, -N NUMBER

--augment-creds=BOOL

--watch-bind=BOOL

--destination=SERVICE

--user

--system

-H, --host=

-M, --machine=

-C, --capsule=

-l, --full

--no-pager

--no-legend

-h, --help

--version

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

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.

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"

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"

SEE ALSO¶

dbus-daemon(1), D-Bus[3], sd-bus(3), varlinkctl(1), systemd(1), machinectl(1), wireshark(1)

NOTES¶

1.

PCAP Next Generation (pcapng) Capture File Format

2.

Type system chapter of the D-Bus specification

3.

D-Bus