=head1 NAME

nbd_aio_get_fd - return file descriptor associated with this connection

=head1 SYNOPSIS

 #include <libnbd.h>

 int nbd_aio_get_fd (
       struct nbd_handle *h
     );

=head1 DESCRIPTION

Return the underlying file descriptor associated with this
connection.  You can use this to check if the file descriptor
is ready for reading or writing and call L<nbd_aio_notify_read(3)>
or L<nbd_aio_notify_write(3)>.  See also L<nbd_aio_get_direction(3)>.
Do not do anything else with the file descriptor.

=head1 RETURN VALUE

This call returns a file descriptor.

=head1 ERRORS

On error C<-1> is returned.

Refer to L<libnbd(3)/ERROR HANDLING>
for how to get further details of the error.

The following parameters must not be NULL: C<h>.
For more information see L<libnbd(3)/Non-NULL parameters>.

=head1 VERSION

This function first appeared in libnbd 1.0.

If you need to test if this function is available at compile time
check if the following macro is defined:

 #define LIBNBD_HAVE_NBD_AIO_GET_FD 1

=head1 SEE ALSO

L<nbd_aio_get_direction(3)>,
L<nbd_aio_notify_read(3)>,
L<nbd_aio_notify_write(3)>,
L<nbd_create(3)>,
L<libnbd(3)>.

=head1 AUTHORS

Eric Blake

Richard W.M. Jones

=head1 COPYRIGHT

Copyright Red Hat
