Lib/uu.py

   1 #! /usr/bin/env python
   2
   3 # Copyright 1994 by Lance Ellinghouse
   4 # Cathedral City, California Republic, United States of America.
   5 #                        All Rights Reserved
   6 # Permission to use, copy, modify, and distribute this software and its
   7 # documentation for any purpose and without fee is hereby granted,
   8 # provided that the above copyright notice appear in all copies and that
   9 # both that copyright notice and this permission notice appear in
  10 # supporting documentation, and that the name of Lance Ellinghouse
  11 # not be used in advertising or publicity pertaining to distribution
  12 # of the software without specific, written prior permission.
  13 # LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO
  14 # THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  15 # FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE
  16 # FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  17 # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  18 # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  19 # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  20 #
  21 # Modified by Jack Jansen, CWI, July 1995:
  22 # - Use binascii module to do the actual line-by-line conversion
  23 #   between ascii and binary. This results in a 1000-fold speedup. The C
  24 #   version is still 5 times faster, though.
  25 # - Arguments more compliant with python standard
  26
  27 """Implementation of the UUencode and UUdecode functions.
  28
  29 encode(in_file, out_file [,name, mode])
  30 decode(in_file [, out_file, mode])
  31 """
  32
  33 import binascii
  34 import os
  35 import sys
  36 from types import StringType
  37
  38 __all__ = ["Error", "encode", "decode"]
  39
  40 class Error(Exception):
  41     pass
  42
  43 def encode(in_file, out_file, name=None, mode=None):
  44     """Uuencode file"""
  45     #
  46     # If in_file is a pathname open it and change defaults
  47     #
  48     if in_file == '-':
  49         in_file = sys.stdin
  50     elif isinstance(in_file, StringType):
  51         if name is None:
  52             name = os.path.basename(in_file)
  53         if mode is None:
  54             try:
  55                 mode = os.stat(in_file)[0]
  56             except AttributeError:
  57                 pass
  58         in_file = open(in_file, 'rb')
  59     #
  60     # Open out_file if it is a pathname
  61     #
  62     if out_file == '-':
  63         out_file = sys.stdout
  64     elif isinstance(out_file, StringType):
  65         out_file = open(out_file, 'w')
  66     #
  67     # Set defaults for name and mode
  68     #
  69     if name is None:
  70         name = '-'
  71     if mode is None:
  72         mode = 0666
  73     #
  74     # Write the data
  75     #
  76     out_file.write('begin %o %s\n' % ((mode&0777),name))
  77     str = in_file.read(45)
  78     while len(str) > 0:
  79         out_file.write(binascii.b2a_uu(str))
  80         str = in_file.read(45)
  81     out_file.write(' \nend\n')
  82
  83
  84 def decode(in_file, out_file=None, mode=None, quiet=0):
  85     """Decode uuencoded file"""
  86     #
  87     # Open the input file, if needed.
  88     #
  89     if in_file == '-':
  90         in_file = sys.stdin
  91     elif isinstance(in_file, StringType):
  92         in_file = open(in_file)
  93     #
  94     # Read until a begin is encountered or we've exhausted the file
  95     #
  96     while 1:
  97         hdr = in_file.readline()
  98         if not hdr:
  99             raise Error, 'No valid begin line found in input file'
 100         if hdr[:5] != 'begin':
 101             continue
 102         hdrfields = hdr.split(" ", 2)
 103         if len(hdrfields) == 3 and hdrfields[0] == 'begin':
 104             try:
 105                 int(hdrfields[1], 8)
 106                 break
 107             except ValueError:
 108                 pass
 109     if out_file is None:
 110         out_file = hdrfields[2].rstrip()
 111         if os.path.exists(out_file):
 112             raise Error, 'Cannot overwrite existing file: %s' % out_file
 113     if mode is None:
 114         mode = int(hdrfields[1], 8)
 115     #
 116     # Open the output file
 117     #
 118     if out_file == '-':
 119         out_file = sys.stdout
 120     elif isinstance(out_file, StringType):
 121         fp = open(out_file, 'wb')
 122         try:
 123             os.path.chmod(out_file, mode)
 124         except AttributeError:
 125             pass
 126         out_file = fp
 127     #
 128     # Main decoding loop
 129     #
 130     s = in_file.readline()
 131     while s and s.strip() != 'end':
 132         try:
 133             data = binascii.a2b_uu(s)
 134         except binascii.Error, v:
 135             # Workaround for broken uuencoders by /Fredrik Lundh
 136             nbytes = (((ord(s[0])-32) & 63) * 4 + 5) / 3
 137             data = binascii.a2b_uu(s[:nbytes])
 138             if not quiet:
 139                 sys.stderr.write("Warning: %s\n" % str(v))
 140         out_file.write(data)
 141         s = in_file.readline()
 142     if not s:
 143         raise Error, 'Truncated input file'
 144
 145 def test():
 146     """uuencode/uudecode main program"""
 147     import getopt
 148
 149     dopt = 0
 150     topt = 0
 151     input = sys.stdin
 152     output = sys.stdout
 153     ok = 1
 154     try:
 155         optlist, args = getopt.getopt(sys.argv[1:], 'dt')
 156     except getopt.error:
 157         ok = 0
 158     if not ok or len(args) > 2:
 159         print 'Usage:', sys.argv[0], '[-d] [-t] [input [output]]'
 160         print ' -d: Decode (in stead of encode)'
 161         print ' -t: data is text, encoded format unix-compatible text'
 162         sys.exit(1)
 163
 164     for o, a in optlist:
 165         if o == '-d': dopt = 1
 166         if o == '-t': topt = 1
 167
 168     if len(args) > 0:
 169         input = args[0]
 170     if len(args) > 1:
 171         output = args[1]
 172
 173     if dopt:
 174         if topt:
 175             if isinstance(output, StringType):
 176                 output = open(output, 'w')
 177             else:
 178                 print sys.argv[0], ': cannot do -t to stdout'
 179                 sys.exit(1)
 180         decode(input, output)
 181     else:
 182         if topt:
 183             if isinstance(input, StringType):
 184                 input = open(input, 'r')
 185             else:
 186                 print sys.argv[0], ': cannot do -t from stdin'
 187                 sys.exit(1)
 188         encode(input, output)
 189
 190 if __name__ == '__main__':
 191     test()