javapythonuuencode

Difference between a uuencoded file using Java and Python

I've to translate a Python code to a Java code and I've got a problem with uuencoding.

Python function:

 import uu
 uu.encode("input_file", "output_file")

Java function:

 MimeUtility.encode(new FileOutputStream(output_file_path), "uuencode");
 stream.write(Files.readAllBytes(input_file));

The result of these functions should be the same uuencoded file, but it is not (they are almost the same). Java uuencoded file is with 2 bytes bigger than the Python.

Where would the problem be?

Edit: An extra byte is added after the name tag (<begin><mode><name>) and a byte after end tag (<end>)

Solution

  • It is a line break issue.

    MIME has always been defined to use CR+LF as terminators, but if using raw encoding such as Python, it is using only LF on Linux. See RFC2045

    # https://github.com/python/cpython/blob/2.7/Lib/uu.py

79         out_file.write('begin %o %s\n' % ((mode&0777),name))

    You should set the os.linesep system variable to '\r\n' so it writes CR+LF line breaks.