подпись сообщения шины запроса (Query bus message signature)
Имя (Name)
sd_bus_message_get_signature, sd_bus_message_is_empty,
sd_bus_message_has_signature - Query bus message signature
Синопсис (Synopsis)
#include <systemd/sd-bus.h>
const char* sd_bus_message_get_signature(sd_bus_message *message,
int complete);
int sd_bus_message_is_empty(sd_bus_message *message);
int sd_bus_message_has_signature(sd_bus_message *message,
const char *signature);
Описание (Description)
sd_bus_message_get_signature() returns the signature of message
message. If complete is true, the signature of the whole message
is returned, and just the signature of the currently open
container otherwise.
sd_bus_message_is_empty() returns true if the message is empty,
i.e. when its signature is empty.
sd_bus_message_has_signature() returns true if the signature of
the message message matches given signature. Parameter signature
may be NULL, this is treated the same as an empty string, which
is equivalent to calling sd_bus_message_is_empty().
Возвращаемое значение (Return value)
On success, sd_bus_message_get_signature() returns the signature,
and NULL on error.
The other functions return 0 or a positive integer on success. On
failure, they return a negative errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
The message parameter is NULL.
NULL
The message parameter is NULL.
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_message_new(3)
