Encode and decode binhex4 files using Python (binhex)

The binhex module encodes and decodes files in binhex4 format, which was used to represent Macintosh files in ASCII format for transmission over text-based protocols. This module handles only the data fork of files.

Functions

The binhex module provides two main functions:

binhex.binhex(input, output): Converts a binary file to binhex4 format. The input parameter is the filename to encode, and output can be either a filename or a file-like object with write() and close() methods.

binhex.hexbin(input, output): Decodes a binhex4 file back to binary format. The input can be a filename or file-like object, and output specifies the destination filename (or None to use the original filename stored in the binhex file).

Encoding a File to Binhex Format

First, let's create a sample text file and encode it to binhex4 format ?

import binhex

# Create a sample file
with open("sample.txt", "w") as f:
    f.write("Hello, this is a test file for binhex encoding!")

# Encode the file to binhex format
binhex.binhex("sample.txt", "sample.hqx")

# Display the encoded content
with open("sample.hqx", "r") as f:
    encoded_content = f.read()
    print("Encoded binhex content:")
    print(encoded_content[:100] + "..." if len(encoded_content) > 100 else encoded_content)

Encoded binhex content:
(This file must be converted with BinHex 4.0)

:#'8FQpZBfpYF'aPH-bk8!!!!%!*!%&8J!!!8P!!!!8J!!!"N8J!!!#%!*!'+!!!!%!!!...

Decoding a Binhex File

Now let's decode the binhex file back to its original format ?

import binhex

# Decode the binhex file
binhex.hexbin("sample.hqx", "decoded_sample.txt")

# Read and display the decoded content
with open("decoded_sample.txt", "r") as f:
    decoded_content = f.read()
    print("Decoded content:")
    print(decoded_content)

Decoded content:
Hello, this is a test file for binhex encoding!

Automatic Filename Detection

When decoding, you can pass None as the output parameter to use the original filename stored in the binhex file ?

import binhex
import os

# Decode using automatic filename detection
binhex.hexbin("sample.hqx", None)

# List files to see what was created
current_files = [f for f in os.listdir('.') if f.startswith('sample')]
print("Files in current directory:")
for file in current_files:
    print(f"  {file}")

Files in current directory:
  sample.txt
  sample.hqx
  decoded_sample.txt

Key Points

• Binhex4 format was primarily used for Macintosh file encoding
• The encoded files typically have a .hqx extension
• Only the data fork is handled, not resource forks
• The format includes a header indicating it should be converted with BinHex 4.0

Conclusion

The binhex module provides simple functions to encode and decode files in binhex4 format. Use binhex.binhex() to encode binary files and binhex.hexbin() to decode them back to their original format.