Provided by: systemd_237-3ubuntu10_amd64 bug


       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:

           Connect to the bus specified by ADDRESS instead of using suitable defaults for either
           the system or user bus (see --system and --user options).

           When showing the list of peers, show a column containing the names of containers they
           belong to. See systemd-machined.service(8).

           When showing the list of peers, show only "unique" names (of the form

           The opposite of --unique — only "well-known" names will be shown.

           When showing the list of peers, show only peers which have actually not been activated
           yet, but may be started automatically if accessed.

           When showing messages being exchanged, show only the subset matching MATCH. See

           When used with the capture command, specifies the maximum bus message size to capture
           ("snaplen"). Defaults to 4096 bytes.

           When used with the tree command, shows a flat list of object paths instead of a tree.

       -q, --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.

           When used with the call or get-property command, shows output in a more verbose

           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

           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".

           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".

           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.

           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".

           Controls whether to wait for the specified AF_UNIX bus socket to appear in the file
           system before connecting to it. Defaults to off. When enabled, the tool will watch the
           file system until the socket is created and then connect to it.

           Talk to the service manager of the calling user, rather than the service manager of
           the 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.

           Do not pipe output into a pager.

           Do not print the legend, i.e. column headers and the footer with hints.

       -h, --help
           Print a short help text and exit.

           Print a short version string and exit.


       The following commands are understood:

           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.

           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.

           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 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.

           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

           # 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

        2. Type system chapter of the D-Bus specification

        3. D-Bus