from utilities import mod2_div
error_message = "\n\nThis script takes one argument, which is the binary frame that is to be CRC encoded."
error_message += "\nThis argument may be piped through the use of echo or can be entered after"
error_message += "the script is run.\nIf you choose the latter, press ctrl-D to end std input after"
error_message += "pressing enter.\n\nExample: echo 1000101001 | python generate.py"
piped_input = stdin.readlines()
if len(piped_input) > 1:
raise ValueError(error_message)
piped_input = piped_input[0].replace("\n", "")
for char in piped_input:
if char != "0" and char != "1":
raise ValueError(error_message)
FRAME = piped_input
GENERATOR = "100000100110000010001110110110111"
#GENERATOR = "10011"
generator_degree = len(GENERATOR) - 1
FRAME = FRAME + ("0" * generator_degree)
division = mod2_div(FRAME, GENERATOR)
tx = bin(int(FRAME, 2) ^ int(division["remainder"],2))[2:]
print tx
from sys import stdin
from utilities import mod2_div
error_message = "\n\nThis script takes one argument, which is a CRC encoded frame in binary."
error_message += "\nThis argument may be piped through the use of echo or can be entered after"
error_message += "the script is run.\nIf you choose the latter, press ctrl-D to end std input after"
error_message += "pressing enter.\n\nExample: echo 11010111110010 | python verify.py"
piped_input = stdin.readlines()
if len(piped_input) > 1:
raise ValueError(error_message)
piped_input = piped_input[0].replace("\n", "")
for char in piped_input:
if char != "0" and char != "1":
raise ValueError(error_message)
CRC_FRAME = piped_input
#GENERATOR = "100000100110000010001110110110111"
GENERATOR = "10011"
generator_degree = len(GENERATOR) - 1
division = mod2_div(CRC_FRAME, GENERATOR)
if division["remainder"] != "0":
print "\nALERT: There was an error in the CRC encoded frame!"
else:
decoded_frame = CRC_FRAME[:-1*generator_degree]
print decoded_frame
