Function: dbus-ping

dbus-ping is a byte-compiled function defined in dbus.el.gz.

Signature

(dbus-ping BUS SERVICE &optional TIMEOUT)

Documentation

Check whether SERVICE is registered for D-Bus BUS.

TIMEOUT, a nonnegative integer, specifies the maximum number of milliseconds before dbus-ping must return. The default value is 25,000.

Note, that this autoloads SERVICE if it is not running yet. To check whether SERVICE is already running, you can instead write

  (member service (dbus-list-known-names bus))

Source Code

;; Defined in /usr/src/emacs/lisp/net/dbus.el.gz
(defun dbus-ping (bus service &optional timeout)
  "Check whether SERVICE is registered for D-Bus BUS.
TIMEOUT, a nonnegative integer, specifies the maximum number of
milliseconds before `dbus-ping' must return.  The default value
is 25,000.

Note, that this autoloads SERVICE if it is not running yet.  To
check whether SERVICE is already running, you can instead write

  (member service (dbus-list-known-names bus))"
  ;; "Ping" raises a D-Bus error if SERVICE does not exist.
  ;; Otherwise, it returns silently with nil.
  (condition-case nil
      (not
       (if (natnump timeout)
	   (dbus-call-method
	    bus service dbus-path-dbus dbus-interface-peer
	    "Ping" :timeout timeout)
	 (dbus-call-method
	  bus service dbus-path-dbus dbus-interface-peer "Ping")))
    (dbus-error nil)))