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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | HISTORY | SEE ALSO | COLOPHON |
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SD_EVE...RIPTION(3) sd_event_source_set_description SD_EVE...RIPTION(3)
sd_event_source_set_description, sd_event_source_get_description -
Set or retrieve descriptive names of event sources
#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 **ret);
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 ret, 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").
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,
library or module instance.
-ENXIO
No name was set for the event source.
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.
sd_event_source_set_description() and
sd_event_source_get_description() were added in version 229.
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)
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 2025-02-02. (At that
time, the date of the most recent commit that was found in the
repository was 2025-02-02.) 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 258~devel SD_EVE...RIPTION(3)
Pages that refer to this page: sd-event(3), sd_event_add_child(3), sd_event_add_defer(3), sd_event_add_inotify(3), sd_event_add_io(3), sd_event_add_memory_pressure(3), sd_event_add_signal(3), sd_event_add_time(3), sd_event_source_set_floating(3), sd_event_source_set_userdata(3), systemd.directives(7), systemd.index(7)
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HTML rendering created 2025-02-02 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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