Utility Program - Magcard Write Read

def interactive_read(card): track = int(input("Enter track to read (1/2/3): ")) data = card.read_track(track) if data: print(f"Track track raw data: data") # Show encoded version for realism encoded = encode_track(data) print(f"Track track encoded (with sentinels + checksum): encoded") # Verify decode decoded = decode_track(encoded) print(f"Decoded & verified: decoded") else: print(f"Track track is empty.") def cli_mode(args): card = MagCard() if args.write: try: track, data = args.write.split(':', 1) track = int(track) card.write_track(track, data) print(f"Written track track: data") except Exception as e: print(f"Error writing: e") if args.read: try: track = int(args.read) data = card.read_track(track) print(f"Track track: data if data else '<empty>'") except Exception as e: print(f"Error reading: e") --- Main interactive menu --- def main(): parser = argparse.ArgumentParser(description="Magnetic Card Read/Write Utility (simulated)") parser.add_argument("--write", help="Write track, format: track:data (e.g., 2:1234567890)") parser.add_argument("--read", help="Read track, e.g., --read 1") args = parser.parse_args()

def interactive_write(card): track = int(input("Enter track to write (1/2/3): ")) data = input(f"Enter data for track track (max TRACK_MAX_LEN[track] chars): ").strip() try: card.write_track(track, data) print(f"Track track written successfully.") except ValueError as e: print(f"Write failed: e") magcard write read utility program

For example, a USB keyboard wedge reader would just capture swiped data as if typed – no special driver needed. A writer would require sending track data in a proprietary command format over USB HID or serial. data = args.write.split(':'

# Verify checksum calc_lrc = 0 for ch in data_part: calc_lrc ^= ord(ch) if chr(calc_lrc % 128) != checksum: raise ValueError("Checksum mismatch – possible read error") return data_part def display_card(card): print("\n=== CURRENT CARD DATA ===") print(f"Track 1: card.track1 if card.track1 else '<empty>'") print(f"Track 2: card.track2 if card.track2 else '<empty>'") print(f"Track 3: card.track3 if card.track3 else '<empty>'") print("=========================\n") 1) track = int(track) card.write_track(track

def clear(self): self.track1 = "" self.track2 = "" self.track3 = "" def encode_track(data, start_sentinel='%', end_sentinel='?'): """Adds start/end sentinels and LRC (simple XOR checksum)""" lrc = 0 for ch in data: lrc ^= ord(ch) checksum_char = chr(lrc % 128) # simple printable approximation return f"start_sentineldataend_sentinelchecksum_char"

def is_valid_track(self, track_num, data): if track_num == 1: return all(ch in TRACK1_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[1] elif track_num == 2: return all(ch in TRACK2_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[2] elif track_num == 3: return all(ch in TRACK3_CHARSET for ch in data) and len(data) <= TRACK_MAX_LEN[3] return False