1  """Python 'uu_codec' Codec - UU content transfer encoding.
       2  
       3  This codec de/encodes from bytes to bytes.
       4  
       5  Written by Marc-Andre Lemburg (mal@lemburg.com). Some details were
       6  adapted from uu.py which was written by Lance Ellinghouse and
       7  modified by Jack Jansen and Fredrik Lundh.
       8  """
       9  
      10  import codecs
      11  import binascii
      12  from io import BytesIO
      13  
      14  ### Codec APIs
      15  
      16  def uu_encode(input, errors='strict', filename='<data>', mode=0o666):
      17      assert errors == 'strict'
      18      infile = BytesIO(input)
      19      outfile = BytesIO()
      20      read = infile.read
      21      write = outfile.write
      22  
      23      # Remove newline chars from filename
      24      filename = filename.replace('\n','\\n')
      25      filename = filename.replace('\r','\\r')
      26  
      27      # Encode
      28      write(('begin %o %s\n' % (mode & 0o777, filename)).encode('ascii'))
      29      chunk = read(45)
      30      while chunk:
      31          write(binascii.b2a_uu(chunk))
      32          chunk = read(45)
      33      write(b' \nend\n')
      34  
      35      return (outfile.getvalue(), len(input))
      36  
      37  def uu_decode(input, errors='strict'):
      38      assert errors == 'strict'
      39      infile = BytesIO(input)
      40      outfile = BytesIO()
      41      readline = infile.readline
      42      write = outfile.write
      43  
      44      # Find start of encoded data
      45      while 1:
      46          s = readline()
      47          if not s:
      48              raise ValueError('Missing "begin" line in input data')
      49          if s[:5] == b'begin':
      50              break
      51  
      52      # Decode
      53      while True:
      54          s = readline()
      55          if not s or s == b'end\n':
      56              break
      57          try:
      58              data = binascii.a2b_uu(s)
      59          except binascii.Error as v:
      60              # Workaround for broken uuencoders by /Fredrik Lundh
      61              nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
      62              data = binascii.a2b_uu(s[:nbytes])
      63              #sys.stderr.write("Warning: %s\n" % str(v))
      64          write(data)
      65      if not s:
      66          raise ValueError('Truncated input data')
      67  
      68      return (outfile.getvalue(), len(input))
      69  
      70  class ESC[4;38;5;81mCodec(ESC[4;38;5;149mcodecsESC[4;38;5;149m.ESC[4;38;5;149mCodec):
      71      def encode(self, input, errors='strict'):
      72          return uu_encode(input, errors)
      73  
      74      def decode(self, input, errors='strict'):
      75          return uu_decode(input, errors)
      76  
      77  class ESC[4;38;5;81mIncrementalEncoder(ESC[4;38;5;149mcodecsESC[4;38;5;149m.ESC[4;38;5;149mIncrementalEncoder):
      78      def encode(self, input, final=False):
      79          return uu_encode(input, self.errors)[0]
      80  
      81  class ESC[4;38;5;81mIncrementalDecoder(ESC[4;38;5;149mcodecsESC[4;38;5;149m.ESC[4;38;5;149mIncrementalDecoder):
      82      def decode(self, input, final=False):
      83          return uu_decode(input, self.errors)[0]
      84  
      85  class ESC[4;38;5;81mStreamWriter(ESC[4;38;5;149mCodec, ESC[4;38;5;149mcodecsESC[4;38;5;149m.ESC[4;38;5;149mStreamWriter):
      86      charbuffertype = bytes
      87  
      88  class ESC[4;38;5;81mStreamReader(ESC[4;38;5;149mCodec, ESC[4;38;5;149mcodecsESC[4;38;5;149m.ESC[4;38;5;149mStreamReader):
      89      charbuffertype = bytes
      90  
      91  ### encodings module API
      92  
      93  def getregentry():
      94      return codecs.CodecInfo(
      95          name='uu',
      96          encode=uu_encode,
      97          decode=uu_decode,
      98          incrementalencoder=IncrementalEncoder,
      99          incrementaldecoder=IncrementalDecoder,
     100          streamreader=StreamReader,
     101          streamwriter=StreamWriter,
     102          _is_text_encoding=False,
     103      )