serialposix.py 文件源码

def in_waiting(self):
        """Return the number of bytes currently in the input buffer."""
        #~ s = fcntl.ioctl(self.fd, termios.FIONREAD, TIOCM_zero_str)
        s = fcntl.ioctl(self.fd, TIOCINQ, TIOCM_zero_str)
        return struct.unpack('I', s)[0]

    # select based implementation, proved to work on many systems