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
  37 __all__ = ["Error", "encode", "decode"]
  38
  39 class Error(Exception):
  40     pass
  41
  42 def encode(in_file, out_file, name=None, mode=None):
  43     """Uuencode file"""
  44     #
  45     # If in_file is a pathname open it and change defaults
  46     #
  47     if in_file == '-':
  48         in_file = sys.stdin
  49     elif type(in_file) == type(''):
  50         if name is None:
  51             name = os.path.basename(in_file)
  52         if mode is None:
  53             try:
  54                 mode = os.stat(in_file)[0]
  55             except AttributeError:
  56                 pass
  57         in_file = open(in_file, 'rb')
  58     #
  59     # Open out_file if it is a pathname
  60     #
  61     if out_file == '-':
  62         out_file = sys.stdout
  63     elif type(out_file) == type(''):
  64         out_file = open(out_file, 'w')
  65     #
  66     # Set defaults for name and mode
  67     #
  68     if name is None:
  69         name = '-'
  70     if mode is None:
  71         mode = 0666
  72     #
  73     # Write the data
  74     #
  75     out_file.write('begin %o %s\n' % ((mode&0777),name))
  76     str = in_file.read(45)
  77     while len(str) > 0:
  78         out_file.write(binascii.b2a_uu(str))
  79         str = in_file.read(45)
  80     out_file.write(' \nend\n')
  81
  82
  83 def decode(in_file, out_file=None, mode=None):
  84     """Decode uuencoded file"""
  85     #
  86     # Open the input file, if needed.
  87     #
  88     if in_file == '-':
  89         in_file = sys.stdin
  90     elif type(in_file) == type(''):
  91         in_file = open(in_file)
  92     #
  93     # Read until a begin is encountered or we've exhausted the file
  94     #
  95     while 1:
  96         hdr = in_file.readline()
  97         if not hdr:
  98             raise Error, 'No valid begin line found in input file'
  99         if hdr[:5] != 'begin':
 100             continue
 101         hdrfields = hdr.split(" ", 2)
 102         if len(hdrfields) == 3 and hdrfields[0] == 'begin':
 103             try:
 104                 int(hdrfields[1], 8)
 105                 break
 106             except ValueError:
 107                 pass
 108     if out_file is None:
 109         out_file = hdrfields[2].rstrip()
 110     if mode is None:
 111         mode = int(hdrfields[1], 8)
 112     #
 113     # Open the output file
 114     #
 115     if out_file == '-':
 116         out_file = sys.stdout
 117     elif type(out_file) == type(''):
 118         fp = open(out_file, 'wb')
 119         try:
 120             os.path.chmod(out_file, mode)
 121         except AttributeError:
 122             pass
 123         out_file = fp
 124     #
 125     # Main decoding loop
 126     #
 127     s = in_file.readline()
 128     while s and s != 'end\n':
 129         try:
 130             data = binascii.a2b_uu(s)
 131         except binascii.Error, v:
 132             # Workaround for broken uuencoders by /Fredrik Lundh
 133             nbytes = (((ord(s[0])-32) & 63) * 4 + 5) / 3
 134             data = binascii.a2b_uu(s[:nbytes])
 135             sys.stderr.write("Warning: %s\n" % str(v))
 136         out_file.write(data)
 137         s = in_file.readline()
 138     if not s:
 139         raise Error, 'Truncated input file'
 140
 141 def test():
 142     """uuencode/uudecode main program"""
 143     import getopt
 144
 145     dopt = 0
 146     topt = 0
 147     input = sys.stdin
 148     output = sys.stdout
 149     ok = 1
 150     try:
 151         optlist, args = getopt.getopt(sys.argv[1:], 'dt')
 152     except getopt.error:
 153         ok = 0
 154     if not ok or len(args) > 2:
 155         print 'Usage:', sys.argv[0], '[-d] [-t] [input [output]]'
 156         print ' -d: Decode (in stead of encode)'
 157         print ' -t: data is text, encoded format unix-compatible text'
 158         sys.exit(1)
 159
 160     for o, a in optlist:
 161         if o == '-d': dopt = 1
 162         if o == '-t': topt = 1
 163
 164     if len(args) > 0:
 165         input = args[0]
 166     if len(args) > 1:
 167         output = args[1]
 168
 169     if dopt:
 170         if topt:
 171             if type(output) == type(''):
 172                 output = open(output, 'w')
 173             else:
 174                 print sys.argv[0], ': cannot do -t to stdout'
 175                 sys.exit(1)
 176         decode(input, output)
 177     else:
 178         if topt:
 179             if type(input) == type(''):
 180                 input = open(input, 'r')
 181             else:
 182                 print sys.argv[0], ': cannot do -t from stdin'
 183                 sys.exit(1)
 184         encode(input, output)
 185
 186 if __name__ == '__main__':
 187     test()