1SD_BUS_ADD_NODE_ENUMERATOR(s3d)_bus_add_node_enumeratSoDr_BUS_ADD_NODE_ENUMERATOR(3)
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6 sd_bus_add_node_enumerator - Add a node enumerator for a D-Bus object
7 path prefix
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10 #include <systemd/sd-bus.h>
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12 typedef int (*sd_bus_node_enumerator_t)(sd_bus *bus,
13 const char *prefix,
14 void *userdata,
15 char ***ret_nodes,
16 sd_bus_error *ret_error);
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18 int sd_bus_add_node_enumerator(sd_bus *bus, sd_bus_slot **slot,
19 const char *path,
20 sd_bus_node_enumerator_t callback,
21 void *userdata);
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24 sd_bus_add_node_enumerator() adds a D-Bus node enumerator for the given
25 path prefix. The given callback is called to enumerate all the
26 available objects with the given path prefix when required (e.g. when
27 org.freedesktop.DBus.Introspectable.Introspect or
28 org.freedesktop.DBus.ObjectManager.GetManagedObjects are called on a
29 D-Bus service managed by sd-bus).
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31 callback is called with the path and userdata pointer registered with
32 sd_bus_add_node_enumerator(). When called, it should store all the
33 child object paths of the given path prefix in ret_nodes and return the
34 number of child objects under the given prefix. If an error occurs, it
35 can either return a negative integer, set ret_error to a non-empty
36 error or do both. Any errors returned by the callback are encoded as
37 D-Bus errors and sent back to the caller. Errors in ret_error take
38 priority over negative return values.
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40 Note that a node enumerator callback will only ever be called for a
41 single path prefix and hence, for normal operation, prefix can be
42 ignored. Also, a node enumerator is only used to enumerate the
43 available child objects under a given prefix. To install a handler for
44 a set of dynamic child objects, use sd_bus_add_fallback_vtable(3).
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46 When sd_bus_add_node_enumerator() succeeds, a slot is created
47 internally. If the output parameter slot is NULL, a "floating" slot
48 object is created, see sd_bus_slot_set_floating(3). Otherwise, a
49 pointer to the slot object is returned. In that case, the reference to
50 the slot object should be dropped when the node enumerator is not
51 needed anymore, see sd_bus_slot_unref(3).
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54 On success, sd_bus_add_node_enumerator() returns a non-negative
55 integer. On failure, it returns a negative errno-style error code.
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57 Errors
58 Returned errors may indicate the following problems:
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60 -EINVAL
61 One of the required parameters is NULL or path is not a valid
62 object path.
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64 -ENOPKG
65 The bus cannot be resolved.
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67 -ECHILD
68 The bus was created in a different process.
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70 -ENOMEM
71 Memory allocation failed.
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74 These APIs are implemented as a shared library, which can be compiled
75 and linked to with the libsystemd pkg-config(1) file.
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78 sd-bus(3), busctl(1), sd_bus_add_fallback_vtable(3),
79 sd_bus_slot_unref(3)
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83systemd 248 SD_BUS_ADD_NODE_ENUMERATOR(3)