The dbus-send command is used to send a message to a D-Bus message bus. See m[blue]http://www.freedesktop.org/software/dbus/m for more information about the big picture.
There are two well-known message buses: the systemwide message bus (installed on many systems as the "messagebus" service) and the per-user-login-session message bus (started each time a user logs in). The --system and --session options direct dbus-send to send messages to the system or session buses respectively. If neither is specified, dbus-send sends to the session bus.
Nearly all uses of dbus-send must provide the --dest argument which is the name of a connection on the bus to send the message to. If --dest is omitted, no destination is set.
The object path and the name of the message to send must always be specified. Following arguments, if any, are the message contents (message arguments). These are given as type-specified values and may include containers (arrays, dicts, and variants) as described below.
<contents> ::= <item> | <container> [ <item> | <container>...] <item> ::= <type>:<value> <container> ::= <array> | <dict> | <variant> <array> ::= array:<type>:<value>[,<value>...] <dict> ::= dict:<type>:<type>:<key>,<value>[,<key>,<value>...] <variant> ::= variant:<type>:<value> <type> ::= string | int16 | uint 16 | int32 | uint32 | int64 | uint64 | double | byte | boolean | objpath
D-Bus supports more types than these, but dbus-send currently does not. Also, dbus-send does not permit empty containers or nested containers (e.g. arrays of variants).
Here is an example invocation:
dbus-send --dest=org.freedesktop.ExampleName \ /org/freedesktop/sample/object/name \ org.freedesktop.ExampleInterface.ExampleMethod \ int32:47 string:'hello world' double:65.32 \ array:string:"1st item","next item","last item" \ dict:string:int32:"one",1,"two",2,"three",3 \ variant:int32:-8 \ objpath:/org/freedesktop/sample/object/name
Note that the interface is separated from a method or signal name by a dot, though in the actual protocol the interface and the interface member are separate fields.