#!/usr/bin/python

import sys, getopt, time

def printDiff(pos, byte1, byte2):

	bits1 = '{0:08b}'.format(byte1)
	bits2 = '{0:08b}'.format(byte2)
	print "@%04Xh" % pos
	print "1:%02Xh, %sb" % (byte1, bits1)
	print "2:%02Xh, %sb" % (byte2, bits2)

def compareFiles(fname1, fname2, offset = 0x0):
	f1 = open(fname1, "rb")
	f1.seek(offset)
	f2 = open(fname2, "rb")
	f2.seek(offset)

	while True:
		c1 = f1.read(1)
		c2 = f2.read(1)
		if not (c1 and c2):
			break
		b1 = ord(c1)
		b2 = ord(c2)
		if b1 != b2:
			pos = f1.tell() - offset
			printDiff(pos, b1, b2)

	pos = f1.tell() - offset
	print "bytes read: %02d" % pos
	f1.close()
	f2.close()

def main(argv):
	file1 = ''
	file2 = ''
	offset = 0x0
	watchmode = False
	opts, args = getopt.getopt(argv,"h1:2:",["file1=","file2=","offset=","watch"])
	if len(opts) < 2:
		opts.append(("-h", ""))
	#print opts		
	for opt, arg in opts:
		if opt == "-h":
			print 'bincmp.py [--offset <start_at_hex_offset>] [--watch] -1 <file1> -2 <file2>'
			sys.exit(1)
		elif opt in ("-1", "--file1"):
			file1 = arg
		elif opt in ("-2", "--file2"):
			file2 = arg
		elif opt == "--offset":
			offset = int(arg, 16)
		elif opt == "--watch":
			watchmode = True
			delay = 5

	print "1:", file1, " 2:", file2

	while True:
		compareFiles(file1, file2, offset)		
		if not watchmode:
			break
		print "------"
		time.sleep(delay)

if __name__ == "__main__":
   main(sys.argv[1:])