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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
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SD_BUS_ADD_NODE_ENUMERATOR(3)us_add_node_enumeratorUS_ADD_NODE_ENUMERATOR(3)
sd_bus_add_node_enumerator - Add a node enumerator for a D-Bus object
path prefix
#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);
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 and return
the number of child objects under the given prefix. 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).
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.
-ENOMEM
Memory allocation failed.
These APIs are implemented as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
sd-bus(3), busctl(1), sd_bus_add_fallback_vtable(3),
sd_bus_slot_unref(3)
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2020-09-18. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-09-18.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
systemd 246 SD_BUS_ADD_NODE_ENUMERATOR(3)
Pages that refer to this page: sd-bus(3), 30-systemd-environment-d-generator(7), systemd.directives(7), systemd.index(7)
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