NAME

       sd_bus_set_fd - Set the file descriptors to use for bus communication

SYNOPSIS

       #include <systemd/sd-bus.h>

       int sd_bus_set_fd(sd_bus *bus, int input_fd, int output_fd);

DESCRIPTION

       sd_bus_set_fd() sets the file descriptors used to communicate by a bus connection object.
       Both input_fd and output_fd must be valid file descriptors, referring to stream-based file
       objects (e.g. a stream socket, a pair of pipes or FIFOs, or even a TTY device).  input_fd
       must be readable, and output_fd must be writable. The same file descriptor may be used
       (and typically is used) as both the input and the output file descriptor. This function
       must be called before the bus connection is started via sd_bus_start(3).

       The bus connection object will take possession of the passed file descriptors and will
       close them automatically when it is freed. Use sd_bus_set_close_on_exit(3) to turn off
       this behaviour.

RETURN VALUE

       On success, sd_bus_set_fd() returns a non-negative integer. On failure, it returns a
       negative errno-style error code.

   Errors
       Returned errors may indicate the following problems:

       -EINVAL
           An invalid bus object was passed.

           Added in version 248.

       -ECHILD
           The bus connection was allocated in a parent process and is being reused in a child
           process after fork().

           Added in version 248.

       -EBADF
           An invalid file descriptor was passed to sd_bus_set_fd().

           Added in version 248.

       -ENOPKG
           The bus cannot be resolved.

           Added in version 248.

       -EPERM
           The bus connection has already been started.

           Added in version 248.

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_set_fd() was added in version 248.

SEE ALSO

       systemd(1), sd-bus(3), sd_bus_get_fd(3), sd_bus_start(3)