установить или получить описательные имена источников событий (Set or retrieve descriptive names of event sources)
Имя (Name)
sd_event_source_set_description, sd_event_source_get_description
- Set or retrieve descriptive names of event sources
Синопсис (Synopsis)
#include <systemd/sd-event.h>
int sd_event_source_set_description(sd_event_source *source,
const char *description);
int sd_event_source_get_description(sd_event_source *source,
const char **description);
Описание (Description)
sd_event_source_set_description() may be used to set an arbitrary
descriptive name for the event source object specified as source.
This name will be used in debugging messages generated by
sd-event(3) for this event source, and may be queried using
sd_event_source_get_description() for debugging purposes. The
description parameter shall point to a NUL-terminated string or
be NULL. In the latter case, the descriptive name will be unset.
The string is copied internally, hence the description argument
is not referenced after the function returns.
sd_event_source_get_description() may be used to query the
current descriptive name assigned to the event source object
source. It returns a pointer to the current name in description,
stored in memory internal to the event source. The memory is
invalidated when the event source is destroyed or the descriptive
name is changed.
Event source objects generally have no description set when they
are created, except for UNIX signal event sources created with
sd_event_add_signal(3), whose descriptive name is initialized to
the signal's C constant name (e.g. "SIGINT" or "SIGTERM").
Возвращаемое значение (Return value)
On success, sd_event_source_set_description() and
sd_event_source_get_description() return a non-negative integer.
On failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
source is not a valid pointer to an sd_event_source object or
the description argument for
sd_event_source_get_description() is NULL.
-ENOMEM
Not enough memory to copy the name.
-ECHILD
The event loop has been created in a different process.
-ENXIO
No name was set for the event source.
Примечание (Note)
These APIs are implemented as a shared library, which can be
compiled and linked to with the libsystemd pkg-config(1) file.
Смотри также (See also)
sd-event(3), sd_event_add_io(3), sd_event_add_time(3),
sd_event_add_signal(3), sd_event_add_child(3),
sd_event_add_inotify(3), sd_event_add_defer(3),
sd_event_source_set_userdata(3)
