ioflush

static VALUE
console_ioflush(VALUE io)
{
    rb_io_t *fptr;
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
    int fd1, fd2;
#endif

    GetOpenFile(io, fptr);
#if defined HAVE_TERMIOS_H || defined HAVE_TERMIO_H
    fd1 = GetReadFD(fptr);
    fd2 = GetWriteFD(fptr);
    if (fd2 != -1 && fd1 != fd2) {
        if (tcflush(fd1, TCIFLUSH)) rb_sys_fail(0);
        if (tcflush(fd2, TCOFLUSH)) rb_sys_fail(0);
    }
    else {
        if (tcflush(fd1, TCIOFLUSH)) rb_sys_fail(0);
    }
#endif
    return io;
}