x SuSE Linux 13.1-RELEASE x
x SuSE Linux 13.1-RELEASEx
SD_BUS_ADD_NODE_ENUMERATORsd_bus_add_node_enumeraSD_BUS_ADD_NODE_ENUMERATOR(3)
NAME
sd_bus_add_node_enumerator - Add a node enumerator for a D-Bus object
path prefix
SYNOPSIS
#include <systemd/sd-bus.h>
typedef int (*sd_bus_node_enumerator_t)(sd_bus *bus,
const char *prefix,
void *userdata,
char ***ret_nodes,
sd_bus_error *ret_error);
int sd_bus_add_node_enumerator(sd_bus *bus, sd_bus_slot **slot,
const char *path,
sd_bus_node_enumerator_t callback,
void *userdata);
DESCRIPTION
sd_bus_add_node_enumerator() adds a D-Bus node enumerator for the given
path prefix. The given callback is called to enumerate all the
available objects with the given path prefix when required (e.g. when
org.freedesktop.DBus.Introspectable.Introspect or
org.freedesktop.DBus.ObjectManager.GetManagedObjects are called on a
D-Bus service managed by sd-bus).
callback is called with the path and userdata pointer registered with
sd_bus_add_node_enumerator(). When called, it should store all the
child object paths of the given path prefix in ret_nodes with a NULL
terminator item. The callback should return a non-negative value on
success. If an error occurs, it can either return a negative integer,
set ret_error to a non-empty error or do both. Any errors returned by
the callback are encoded as D-Bus errors and sent back to the caller.
Errors in ret_error take priority over negative return values.
Note that a node enumerator callback will only ever be called for a
single path prefix and hence, for normal operation, prefix can be
ignored. Also, a node enumerator is only used to enumerate the
available child objects under a given prefix. To install a handler for
a set of dynamic child objects, use sd_bus_add_fallback_vtable(3).
When sd_bus_add_node_enumerator() succeeds, a slot is created
internally. If the output parameter slot is NULL, a "floating" slot
object is created, see sd_bus_slot_set_floating(3). Otherwise, a
pointer to the slot object is returned. In that case, the reference to
the slot object should be dropped when the node enumerator is not
needed anymore, see sd_bus_slot_unref(3).
RETURN VALUE
On success, sd_bus_add_node_enumerator() returns a non-negative
integer. On failure, it returns a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
One of the required parameters is NULL or path is not a valid
object path.
-ENOPKG
The bus cannot be resolved.
-ECHILD
The bus was created in a different process, library or module
instance.
-ENOMEM
Memory allocation failed.
NOTES
Functions described here are available as a shared library, which can
be compiled against and linked to with the libsystemd pkg-config(1)
file.
The code described here uses getenv(3), which is declared to be not
multi-thread-safe. This means that the code calling the functions
described here must not call setenv(3) from a parallel thread. It is
recommended to only do calls to setenv() from an early phase of the
program when no other threads have been started.
SEE ALSO
sd-bus(3), busctl(1), sd_bus_add_fallback_vtable(3),
sd_bus_slot_unref(3)
systemd 254 SD_BUS_ADD_NODE_ENUMERATOR(3)
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