UUencode Encode/Decode
Unix-to-Unix Encoding
UUencode Encoding Guide
Encoding Format Example
- begin 644 filename.txt
- Each line: length char + encoded data
- Length char = actual bytes + 32 (space)
- Empty line marked with ` (length 0 + 32)
Encoding Principle
- Convert every 3 bytes of binary data into 4 printable characters
- Character range: Space (0x20) to Backtick (0x60), 64 total
- Each line starts with a length byte, space + length value indicates byte count
- Encoded char = original byte + 32 (space)
History & Modern Alternatives
- Early Unix uucp email transport
- Usenet newsgroup binary file transfer
- Now replaced by Base64 and Base85
- Only used for legacy data compatibility and decoding old files