установка и запрос информации об адресации сообщений шины (set and query bus message addressing information)
Имя (Name)
sd_bus_message_set_destination, sd_bus_message_get_destination,
sd_bus_message_get_path, sd_bus_message_get_interface,
sd_bus_message_get_member, sd_bus_message_set_sender,
sd_bus_message_get_sender - Set and query bus message addressing
information
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
int sd_bus_message_set_destination(sd_bus_message *message,
const char *destination);
const char*
sd_bus_message_get_destination(sd_bus_message *message);
const char* sd_bus_message_get_path(sd_bus_message *message);
const char*
sd_bus_message_get_interface(sd_bus_message *message);
const char* sd_bus_message_get_member(sd_bus_message *message);
int sd_bus_message_set_sender(sd_bus_message *message,
const char *sender);
const char* sd_bus_message_get_sender(sd_bus_message *message);
Описание (Description)
sd_bus_message_set_destination() sets the destination service
name for the specified bus message object. The specified name
must be a valid unique or well-known service name.
sd_bus_message_get_destination(), sd_bus_message_get_path(),
sd_bus_message_get_interface(), and sd_bus_message_get_member()
return the destination, path, interface, and member fields from
message header. The return value will be NULL is message is NULL
or the message is of a type that doesn't use those fields or the
message doesn't have them set. See
sd_bus_message_new_method_call(3) and
sd_bus_message_set_destination(3) for more discussion of those
values.
sd_bus_message_set_sender() sets the sender service name for the
specified bus message object. The specified name must be a valid
unique or well-known service name. This function is useful only
for messages to send on direct connections as for connections to
bus brokers the broker will fill in the destination field anyway,
and the sender field set by original sender is ignored.
sd_bus_message_get_sender() returns the sender field from
message.
When a string is returned, it is a pointer to internal storage,
and may not be modified or freed. It is only valid as long as the
message remains referenced and this field hasn't been changed by
a different call.
Возвращаемое значение (Return value)
On success, these calls return 0 or a positive integer. On
failure, these calls return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The message parameter or the output parameter are NULL.
-EPERM
For sd_bus_message_set_destination() and
sd_bus_message_set_sender(), the message is already sealed.
-EEXIST
The message already has a destination or sender field set.
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)
systemd(1), sd-bus(3), sd_bus_new(3), sd_bus_set_sender(3)
