|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_BUS_SEND(3) sd_bus_send SD_BUS_SEND(3)
sd_bus_send, sd_bus_send_to - Queue a D-Bus message for transfer
#include <systemd/sd-bus.h>
int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *cookie);
int sd_bus_send_to(sd_bus *bus, sd_bus_message *m,
const char *destination, uint64_t *cookie);
sd_bus_send() queues the bus message object m for transfer. If bus is
NULL, the bus that m is attached to is used. bus only needs to be
set when the message is sent to a different bus than the one it's
attached to, for example when forwarding messages. If the output
parameter cookie is not NULL, it is set to the message identifier.
This value can later be used to match incoming replies to their
corresponding messages. If cookie is set to NULL and the message is
not sealed, sd_bus_send() assumes the message m doesn't expect a
reply and adds the necessary headers to indicate this.
Note that in most scenarios, sd_bus_send() should not be called
directly. Instead, use higher level functions such as
sd_bus_call_method(3) and sd_bus_reply_method_return(3) which call
sd_bus_send() internally.
sd_bus_send_to() is a shorthand for sending a message to a specific
destination. It's main use case is to simplify sending unicast signal
messages (signals that only have a single receiver). It's behavior is
similar to calling sd_bus_message_set_destination(3) followed by
calling sd_bus_send().
On success, these functions return a non-negative integer. On
failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The input parameter m is NULL.
-EOPNOTSUPP
The bus connection does not support sending file descriptors.
-ECHILD
The bus connection was allocated in a parent process and is being
reused in a child process after fork().
-ENOBUFS
The bus connection's write queue is full.
-ENOTCONN
The input parameter bus is NULL or the bus is not connected.
-ECONNRESET
The bus connection was closed while waiting for the response.
-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.
systemd(1), sd-bus(3), sd_bus_call_method(3),
sd_bus_message_set_destination(3), sd_bus_reply_method_return(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 2020-08-13. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-08-11.) 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_SEND(3)
Pages that refer to this page: sd-bus(3) , sd_bus_default(3) , sd_bus_default_system(3) , sd_bus_default_user(3) , sd_bus_emit_interfaces_added(3) , sd_bus_emit_interfaces_added_strv(3) , sd_bus_emit_interfaces_removed(3) , sd_bus_emit_interfaces_removed_strv(3) , sd_bus_emit_object_added(3) , sd_bus_emit_object_removed(3) , sd_bus_emit_properties_changed(3) , sd_bus_emit_properties_changed_strv(3) , sd_bus_emit_signal(3) , sd_bus_emit_signalv(3) , sd_bus_enqueue_for_read(3) , sd_bus_get_n_queued_read(3) , sd_bus_get_n_queued_write(3) , sd_bus_get_watch_bind(3) , sd_bus_message_seal(3) , sd_bus_open(3) , sd_bus_open_system(3) , sd_bus_open_system_machine(3) , sd_bus_open_system_remote(3) , sd_bus_open_system_with_description(3) , sd_bus_open_user(3) , sd_bus_open_user_with_description(3) , sd_bus_open_with_description(3) , sd_bus_set_watch_bind(3) , sd_bus_start(3) , 30-systemd-environment-d-generator(7) , systemd.directives(7) , systemd.index(7)