dbus-register-signal is a compiled Lisp function in `
(dbus-register-signal BUS SERVICE PATH INTERFACE SIGNAL HANDLER &rest ARGS)
Register for a signal on the D-Bus BUS.
BUS is either a Lisp symbol, `:system' or `:session', or a string
denoting the bus address.
SERVICE is the D-Bus service name used by the sending D-Bus object.
It can be either a known name or the unique name of the D-Bus object
sending the signal.
PATH is the D-Bus object path SERVICE is registered. INTERFACE
is an interface offered by SERVICE. It must provide SIGNAL.
HANDLER is a Lisp function to be called when the signal is
received. It must accept as arguments the values SIGNAL is
SERVICE, PATH, INTERFACE and SIGNAL can be nil. This is
interpreted as a wildcard for the respective argument.
The remaining arguments ARGS can be keywords or keyword string pairs.
The meaning is as follows:
`:pathN' STRING: This stands for the Nth argument of the
signal. `:pathN' arguments can be used for object path wildcard
matches as specified by D-Bus, while an `:argN' argument
requires an exact match.
`:arg-namespace' STRING: Register for the signals, which first
argument defines the service or interface namespace STRING.
`:path-namespace' STRING: Register for the object path namespace
STRING. All signals sent from an object path, which has STRING as
the preceding string, are matched. This requires PATH to be nil.
`:eavesdrop': Register for unicast signals which are not directed
to the D-Bus object Emacs is registered at D-Bus BUS, if the
security policy of BUS allows this.
(defun my-signal-handler (device)
(message "Device %s added" device))
:system "org.freedesktop.Hal" "/org/freedesktop/Hal/Manager"
"org.freedesktop.Hal.Manager" "DeviceAdded" 'my-signal-handler)
=> ((:signal :system "org.freedesktop.Hal.Manager" "DeviceAdded")
("org.freedesktop.Hal" "/org/freedesktop/Hal/Manager" my-signal-handler))
`dbus-register-signal' returns an object, which can be used in
`dbus-unregister-object' for removing the registration.