sd_bus_message_new_signal - Create a signal message

NAME SYNOPSIS DESCRIPTION RETURN VALUE Errors NOTES SEE ALSO

NAME

sd_bus_message_new_signal, sd_bus_message_new_signal_to − Create a signal message

SYNOPSIS

#include <elogind/sd−bus.h>

	int sd_bus_message_new_signal(sd_bus *bus, sd_bus_message m, const char path, const char interface, const char *member);
	int sd_bus_message_new_signal_to(sd_bus *bus, sd_bus_message m, const char destination, const char path, const char *interface, const char *member);

The sd_bus_message_new_signal() function creates a new bus message object that encapsulates a D−Bus signal, and returns it in the m output parameter. The signal will be sent to path path, on the interface interface, member member. When this message is sent, no reply is expected. See sd_bus_message_new_method_call(1) for a short description of the meaning of the path, interface, and member parameters.

sd_bus_message_new_signal_to() is a shorthand for creating a new bus message to a specific destination. It's behavior is similar to calling sd_bus_message_new_signal() followed by calling sd_bus_message_set_destination(3).

RETURN VALUE

This function returns 0 if the message object was successfully created, and a negative errno−style error code otherwise.

Errors

Returned errors may indicate the following problems:

−EINVAL

The output parameter m is NULL.

The path parameter is not a valid D−Bus path ("/an/object/path"), the interface parameter is not a valid D−Bus interface name ("an.interface.name"), or the member parameter is not a valid D−Bus member ("Name").

−ENOTCONN

The bus parameter bus is NULL or the bus is not connected.

−ENOMEM

Memory allocation failed.

NOTES

Functions described here are available as a shared library, which can be compiled against and linked to with the libelogind pkg-config(8) file.