sd_bus_can_send - Man Page
Check which types can be sent over a bus object
Synopsis
#include <systemd/sd-bus.h>
int 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.
All functions listed here are thread-agnostic and only a single thread may operate on a given object at any given time. Different threads may access the same object at different times. Multiple independent objects may be used from different threads in parallel.
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.
See Also
Referenced By
sd-bus(3), sd_bus_negotiate_fds(3), systemd.directives(7), systemd.index(7).