1BUSCTL(1) busctl BUSCTL(1)
2
6 busctl - Introspect the bus
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9 busctl [OPTIONS...] [COMMAND] [NAME...]
10
12 busctl may be used to introspect and monitor the D-Bus bus.
13
15 The following options are understood:
16 --address=ADDRESS
18 Connect to the bus specified by ADDRESS instead of using suitable
19 defaults for either the system or user bus (see --system and --user
20 options).
21 --show-machine
23 When showing the list of peers, show a column containing the names
24 of containers they belong to. See systemd-machined.service(8).
25 --unique
27 When showing the list of peers, show only "unique" names (of the
28 form ":number.number").
29 --acquired
31 The opposite of --unique — only "well-known" names will be shown.
32 --activatable
34 When showing the list of peers, show only peers which have actually
35 not been activated yet, but may be started automatically if
36 accessed.
37 --match=MATCH
39 When showing messages being exchanged, show only the subset
40 matching MATCH. See sd_bus_add_match(3).
41 --size=
43 When used with the capture command, specifies the maximum bus
44 message size to capture ("snaplen"). Defaults to 4096 bytes.
45 --list
47 When used with the tree command, shows a flat list of object paths
48 instead of a tree.
49 -q, --quiet
51 When used with the call command, suppresses display of the response
52 message payload. Note that even if this option is specified, errors
53 returned will still be printed and the tool will indicate success
54 or failure with the process exit code.
55 --verbose
57 When used with the call or get-property command, shows output in a
58 more verbose format.
59 --expect-reply=BOOL
61 When used with the call command, specifies whether busctl shall
62 wait for completion of the method call, output the returned method
63 response data, and return success or failure via the process exit
64 code. If this is set to "no", the method call will be issued but no
65 response is expected, the tool terminates immediately, and thus no
66 response can be shown, and no success or failure is returned via
67 the exit code. To only suppress output of the reply message
68 payload, use --quiet above. Defaults to "yes".
69 --auto-start=BOOL
71 When used with the call command, specifies whether the method call
72 should implicitly activate the called service, should it not be
73 running yet but is configured to be auto-started. Defaults to
74 "yes".
75 --allow-interactive-authorization=BOOL
77 When used with the call command, specifies whether the services may
78 enforce interactive authorization while executing the operation, if
79 the security policy is configured for this. Defaults to "yes".
80 --timeout=SECS
82 When used with the call command, specifies the maximum time to wait
83 for method call completion. If no time unit is specified, assumes
84 seconds. The usual other units are understood, too (ms, us, s, min,
85 h, d, w, month, y). Note that this timeout does not apply if
86 --expect-reply=no is used, as the tool does not wait for any reply
87 message then. When not specified or when set to 0, the default of
88 "25s" is assumed.
89 --augment-creds=BOOL
91 Controls whether credential data reported by list or status shall
92 be augmented with data from /proc. When this is turned on, the data
93 shown is possibly inconsistent, as the data read from /proc might
94 be more recent than the rest of the credential information.
95 Defaults to "yes".
96 --watch-bind=BOOL
98 Controls whether to wait for the specified AF_UNIX bus socket to
99 appear in the file system before connecting to it. Defaults to off.
100 When enabled, the tool will watch the file system until the socket
101 is created and then connect to it.
102 --user
104 Talk to the service manager of the calling user, rather than the
105 service manager of the system.
106 --system
108 Talk to the service manager of the system. This is the implied
109 default.
110 -H, --host=
112 Execute the operation remotely. Specify a hostname, or a username
113 and hostname separated by "@", to connect to. The hostname may
114 optionally be suffixed by a container name, separated by ":", which
115 connects directly to a specific container on the specified host.
116 This will use SSH to talk to the remote machine manager instance.
117 Container names may be enumerated with machinectl -H HOST.
118 -M, --machine=
120 Execute operation on a local container. Specify a container name to
121 connect to.
122 --no-pager
124 Do not pipe output into a pager.
125 --no-legend
127 Do not print the legend, i.e. column headers and the footer with
128 hints.
129 -h, --help
131 Print a short help text and exit.
132 --version
134 Print a short version string and exit.
135
137 The following commands are understood:
138 list
140 Show all peers on the bus, by their service names. By default,
141 shows both unique and well-known names, but this may be changed
142 with the --unique and --acquired switches. This is the default
143 operation if no command is specified.
144 status [SERVICE]
146 Show process information and credentials of a bus service (if one
147 is specified by its unique or well-known name), a process (if one
148 is specified by its numeric PID), or the owner of the bus (if no
149 parameter is specified).
150 monitor [SERVICE...]
152 Dump messages being exchanged. If SERVICE is specified, show
153 messages to or from this peer, identified by its well-known or
154 unique name. Otherwise, show all messages on the bus. Use Ctrl-C to
155 terminate the dump.
156 capture [SERVICE...]
158 Similar to monitor but writes the output in pcap format (for
159 details, see the Libpcap File Format[1] description). Make sure to
160 redirect standard output to a file. Tools like wireshark(1) may be
161 used to dissect and view the resulting files.
162 tree [SERVICE...]
164 Shows an object tree of one or more services. If SERVICE is
165 specified, show object tree of the specified services only.
166 Otherwise, show all object trees of all services on the bus that
167 acquired at least one well-known name.
168 introspect SERVICE OBJECT [INTERFACE]
170 Show interfaces, methods, properties and signals of the specified
171 object (identified by its path) on the specified service. If the
172 interface argument is passed, the output is limited to members of
173 the specified interface.
174 call SERVICE OBJECT INTERFACE METHOD [SIGNATURE [ARGUMENT...]]
176 Invoke a method and show the response. Takes a service name, object
177 path, interface name and method name. If parameters shall be passed
178 to the method call, a signature string is required, followed by the
179 arguments, individually formatted as strings. For details on the
180 formatting used, see below. To suppress output of the returned
181 data, use the --quiet option.
182 get-property SERVICE OBJECT INTERFACE PROPERTY...
184 Retrieve the current value of one or more object properties. Takes
185 a service name, object path, interface name and property name.
186 Multiple properties may be specified at once, in which case their
187 values will be shown one after the other, separated by newlines.
188 The output is, by default, in terse format. Use --verbose for a
189 more elaborate output format.
190 set-property SERVICE OBJECT INTERFACE PROPERTY SIGNATURE ARGUMENT...
192 Set the current value of an object property. Takes a service name,
193 object path, interface name, property name, property signature,
194 followed by a list of parameters formatted as strings.
195 help
197 Show command syntax help.
198
200 The call and set-property commands take a signature string followed by
201 a list of parameters formatted as string (for details on D-Bus
202 signature strings, see the Type system chapter of the D-Bus
203 specification[2]). For simple types, each parameter following the
204 signature should simply be the parameter's value formatted as string.
205 Positive boolean values may be formatted as "true", "yes", "on", or
206 "1"; negative boolean values may be specified as "false", "no", "off",
207 or "0". For arrays, a numeric argument for the number of entries
208 followed by the entries shall be specified. For variants, the signature
209 of the contents shall be specified, followed by the contents. For
210 dictionaries and structs, the contents of them shall be directly
211 specified.
212 For example,
214 s jawoll
216 is the formatting of a single string "jawoll".
218 as 3 hello world foobar
220 is the formatting of a string array with three entries, "hello",
222 "world" and "foobar".
223 a{sv} 3 One s Eins Two u 2 Yes b true
225 is the formatting of a dictionary array that maps strings to variants,
227 consisting of three entries. The string "One" is assigned the string
228 "Eins". The string "Two" is assigned the 32-bit unsigned integer 2. The
229 string "Yes" is assigned a positive boolean.
230 Note that the call, get-property, introspect commands will also
232 generate output in this format for the returned data. Since this format
233 is sometimes too terse to be easily understood, the call and
234 get-property commands may generate a more verbose, multi-line output
235 when passed the --verbose option.
236
238 Example 1. Write and Read a Property
239 The following two commands first write a property and then read it
241 back. The property is found on the "/org/freedesktop/systemd1" object
242 of the "org.freedesktop.systemd1" service. The name of the property is
243 "LogLevel" on the "org.freedesktop.systemd1.Manager" interface. The
244 property contains a single string:
245 # busctl set-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel s debug
247 # busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager LogLevel
248 s "debug"
249 Example 2. Terse and Verbose Output
251 The following two commands read a property that contains an array of
253 strings, and first show it in terse format, followed by verbose format:
254 $ busctl get-property org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
256 as 2 "LANG=en_US.UTF-8" "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin"
257 $ busctl get-property --verbose org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager Environment
258 ARRAY "s" {
259 STRING "LANG=en_US.UTF-8";
260 STRING "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin";
261 };
262 Example 3. Invoking a Method
264 The following command invokes the "StartUnit" method on the
266 "org.freedesktop.systemd1.Manager" interface of the
267 "/org/freedesktop/systemd1" object of the "org.freedesktop.systemd1"
268 service, and passes it two strings "cups.service" and "replace". As a
269 result of the method call, a single object path parameter is received
270 and shown:
271 # busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.systemd1.Manager StartUnit ss "cups.service" "replace"
273 o "/org/freedesktop/systemd1/job/42684"
274
276 dbus-daemon(1), D-Bus[3], sd-bus(3), systemd(1), machinectl(1),
277 wireshark(1)
278
280 1. Libpcap File Format
281 https://wiki.wireshark.org/Development/LibpcapFileFormat
282 2. Type system chapter of the D-Bus specification
284 http://dbus.freedesktop.org/doc/dbus-specification.html#type-system
285 3. D-Bus
287 https://www.freedesktop.org/wiki/Software/dbus
288systemd 239 BUSCTL(1)