table of contents
- bullseye 247.3-7+deb11u1
- bullseye-backports 252.5-2~bpo11+1
- testing 252.5-2
- unstable 252.6-1
- experimental 253-1
SD_BUS_MESSAGE_GET_SIGNATURE(3) | sd_bus_message_get_signature | SD_BUS_MESSAGE_GET_SIGNATURE(3) |
NAME¶
sd_bus_message_get_signature, sd_bus_message_is_empty, sd_bus_message_has_signature - Query bus message signature
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);
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().
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
NULL
NOTES¶
These APIs are implemented as a shared library, which can be compiled and linked to with the libsystemd pkg-config(1) file.
SEE ALSO¶
systemd 247 |