Section: sd_bus_send (3)
sd_bus_send, sd_bus_send_to, sd_bus_message_send - Queue a D-Bus message for transfer
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);
int sd_bus_message_send(sd_bus_message *m);
queues the bus message object
for transfer. If
NULL, the bus that
is attached to is used.
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
NULL, it is set to the message identifier. This value can later be used to match incoming replies to their corresponding messages. If
is set to
and the message is not sealed,
assumes the message
doesn't expect a reply and adds the necessary headers to indicate this.
Note that in most scenarios,
should not be called directly. Instead, use higher level functions such as
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
followed by calling
will write the message directly to the underlying transport (e.g. kernel socket buffer) if possible. If the connection is not set up fully yet the message is queued locally. If the transport buffers are congested any unwritten message data is queued locally, too. If the connection has been closed or is currently being closed the call fails.
should be invoked to write out any queued message data to the transport.
is the same as
but without the first and last argument.
is equivalent to
sd_bus_send(sd_bus_message_get_bus(m), m, NULL).
On success, these functions return a non-negative integer. On failure, they return a negative errno-style error code.
Returned errors may indicate the following problems:
The input parameter
The bus connection does not support sending file descriptors.
The bus connection was allocated in a parent process and is being reused in a child process after
The bus connection's write queue is full.
The input parameter
or the bus is not connected.
The bus connection was closed while waiting for the response.
Memory allocation failed.
These APIs are implemented as a shared library, which can be compiled and linked to with the