sd_bus_can_send — Check which types can be sent over a bus object
#include <systemd/sd-bus.h>
| void sd_bus_can_send( | sd_bus *bus, | 
| char type ); | 
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.
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.
These APIs are implemented as a shared
  library, which can be compiled and linked to with the
  libsystemd pkg-config(1)
  file.