sd_bus_can

Name

sd_bus_can_send — Check which types can be sent over a bus object

Synopsis

#include <systemd/sd-bus.h>

`void sd_bus_can_send(`	sd_bus *`bus`,
	char `type)`;

Description¶

sd_bus_can_send() is mostly used for checking if file descriptor passing is available on the given bus. type can be any of the SD_BUS_TYPE constants.

Return Value¶

On failure, sd_bus_can_send() returns a negative errno-style error code. If values of the given type can be sent over the given bus, it returns a positive integer. Otherwise, it returns zero.

Errors¶

Returned errors may indicate the following problems:

-ENOPKG¶: The bus object bus could not be resolved.
-ENOTCONN¶: The input parameter bus is NULL or the bus is not connected.
-ECHILD¶: The bus object bus was created in a different process.

Notes¶

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemd pkg-config(1) file.

The code described here uses getenv(3), which is declared to be not multi-thread-safe. This means that the code calling the functions described here must not call setenv(3) from a parallel thread. It is recommended to only do calls to setenv() from an early phase of the program when no other threads have been started.

History¶

sd_bus_can_send() was added in version 221.