LIRC mode2 support #13

#!/usr/bin/env python

import fcntl
import array
import os
import struct

LIRC_GET_REC_MODE = 0x80046902 # _IOR('i', 0x00000002, __u32)
LIRC_GET_LENGTH = 0x8004690F # _IOR('i', 0x0000000f, __u32)
LIRC_MODE_MODE2 = 0x00000004
PULSE_BIT = 0x01000000
PULSE_MASK = 0x00FFFFFF

result = array.array("I", [0])

lirc_t = "i"

def read(fd):
  rawbuf = os.read(fd, struct.calcsize(lirc_t))
  rawvalue, = struct.unpack(lirc_t, rawbuf)
  pulseflag = rawvalue & PULSE_BIT
  duration = rawvalue & PULSE_MASK
  return (pulseflag != 0, duration)

def main():
  fd = os.open("/dev/lirc0", os.O_RDONLY)
  if fcntl.ioctl(fd, LIRC_GET_REC_MODE, result, True) == -1:
    raise IOError("cannot use {!r} as a raw LIRC device. Is it a
LIRC device?".format(self.device))
  if result[0] != LIRC_MODE_MODE2:
    raise IOError("cannot use {!r} as a raw LIRC device. Is it a
raw (!) LIRC device?".format(self.device))
  print(read(fd))