uu.py 7.1 KB

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  1. #! /usr/bin/env python3
  2. # Copyright 1994 by Lance Ellinghouse
  3. # Cathedral City, California Republic, United States of America.
  4. # All Rights Reserved
  5. # Permission to use, copy, modify, and distribute this software and its
  6. # documentation for any purpose and without fee is hereby granted,
  7. # provided that the above copyright notice appear in all copies and that
  8. # both that copyright notice and this permission notice appear in
  9. # supporting documentation, and that the name of Lance Ellinghouse
  10. # not be used in advertising or publicity pertaining to distribution
  11. # of the software without specific, written prior permission.
  12. # LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO
  13. # THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
  14. # FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE
  15. # FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  16. # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  17. # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  18. # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  19. #
  20. # Modified by Jack Jansen, CWI, July 1995:
  21. # - Use binascii module to do the actual line-by-line conversion
  22. # between ascii and binary. This results in a 1000-fold speedup. The C
  23. # version is still 5 times faster, though.
  24. # - Arguments more compliant with python standard
  25. """Implementation of the UUencode and UUdecode functions.
  26. encode(in_file, out_file [,name, mode], *, backtick=False)
  27. decode(in_file [, out_file, mode, quiet])
  28. """
  29. import binascii
  30. import os
  31. import sys
  32. __all__ = ["Error", "encode", "decode"]
  33. class Error(Exception):
  34. pass
  35. def encode(in_file, out_file, name=None, mode=None, *, backtick=False):
  36. """Uuencode file"""
  37. #
  38. # If in_file is a pathname open it and change defaults
  39. #
  40. opened_files = []
  41. try:
  42. if in_file == '-':
  43. in_file = sys.stdin.buffer
  44. elif isinstance(in_file, str):
  45. if name is None:
  46. name = os.path.basename(in_file)
  47. if mode is None:
  48. try:
  49. mode = os.stat(in_file).st_mode
  50. except AttributeError:
  51. pass
  52. in_file = open(in_file, 'rb')
  53. opened_files.append(in_file)
  54. #
  55. # Open out_file if it is a pathname
  56. #
  57. if out_file == '-':
  58. out_file = sys.stdout.buffer
  59. elif isinstance(out_file, str):
  60. out_file = open(out_file, 'wb')
  61. opened_files.append(out_file)
  62. #
  63. # Set defaults for name and mode
  64. #
  65. if name is None:
  66. name = '-'
  67. if mode is None:
  68. mode = 0o666
  69. #
  70. # Remove newline chars from name
  71. #
  72. name = name.replace('\n','\\n')
  73. name = name.replace('\r','\\r')
  74. #
  75. # Write the data
  76. #
  77. out_file.write(('begin %o %s\n' % ((mode & 0o777), name)).encode("ascii"))
  78. data = in_file.read(45)
  79. while len(data) > 0:
  80. out_file.write(binascii.b2a_uu(data, backtick=backtick))
  81. data = in_file.read(45)
  82. if backtick:
  83. out_file.write(b'`\nend\n')
  84. else:
  85. out_file.write(b' \nend\n')
  86. finally:
  87. for f in opened_files:
  88. f.close()
  89. def decode(in_file, out_file=None, mode=None, quiet=False):
  90. """Decode uuencoded file"""
  91. #
  92. # Open the input file, if needed.
  93. #
  94. opened_files = []
  95. if in_file == '-':
  96. in_file = sys.stdin.buffer
  97. elif isinstance(in_file, str):
  98. in_file = open(in_file, 'rb')
  99. opened_files.append(in_file)
  100. try:
  101. #
  102. # Read until a begin is encountered or we've exhausted the file
  103. #
  104. while True:
  105. hdr = in_file.readline()
  106. if not hdr:
  107. raise Error('No valid begin line found in input file')
  108. if not hdr.startswith(b'begin'):
  109. continue
  110. hdrfields = hdr.split(b' ', 2)
  111. if len(hdrfields) == 3 and hdrfields[0] == b'begin':
  112. try:
  113. int(hdrfields[1], 8)
  114. break
  115. except ValueError:
  116. pass
  117. if out_file is None:
  118. # If the filename isn't ASCII, what's up with that?!?
  119. out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii")
  120. if os.path.exists(out_file):
  121. raise Error(f'Cannot overwrite existing file: {out_file}')
  122. if (out_file.startswith(os.sep) or
  123. f'..{os.sep}' in out_file or (
  124. os.altsep and
  125. (out_file.startswith(os.altsep) or
  126. f'..{os.altsep}' in out_file))
  127. ):
  128. raise Error(f'Refusing to write to {out_file} due to directory traversal')
  129. if mode is None:
  130. mode = int(hdrfields[1], 8)
  131. #
  132. # Open the output file
  133. #
  134. if out_file == '-':
  135. out_file = sys.stdout.buffer
  136. elif isinstance(out_file, str):
  137. fp = open(out_file, 'wb')
  138. os.chmod(out_file, mode)
  139. out_file = fp
  140. opened_files.append(out_file)
  141. #
  142. # Main decoding loop
  143. #
  144. s = in_file.readline()
  145. while s and s.strip(b' \t\r\n\f') != b'end':
  146. try:
  147. data = binascii.a2b_uu(s)
  148. except binascii.Error as v:
  149. # Workaround for broken uuencoders by /Fredrik Lundh
  150. nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
  151. data = binascii.a2b_uu(s[:nbytes])
  152. if not quiet:
  153. sys.stderr.write("Warning: %s\n" % v)
  154. out_file.write(data)
  155. s = in_file.readline()
  156. if not s:
  157. raise Error('Truncated input file')
  158. finally:
  159. for f in opened_files:
  160. f.close()
  161. def test():
  162. """uuencode/uudecode main program"""
  163. import optparse
  164. parser = optparse.OptionParser(usage='usage: %prog [-d] [-t] [input [output]]')
  165. parser.add_option('-d', '--decode', dest='decode', help='Decode (instead of encode)?', default=False, action='store_true')
  166. parser.add_option('-t', '--text', dest='text', help='data is text, encoded format unix-compatible text?', default=False, action='store_true')
  167. (options, args) = parser.parse_args()
  168. if len(args) > 2:
  169. parser.error('incorrect number of arguments')
  170. sys.exit(1)
  171. # Use the binary streams underlying stdin/stdout
  172. input = sys.stdin.buffer
  173. output = sys.stdout.buffer
  174. if len(args) > 0:
  175. input = args[0]
  176. if len(args) > 1:
  177. output = args[1]
  178. if options.decode:
  179. if options.text:
  180. if isinstance(output, str):
  181. output = open(output, 'wb')
  182. else:
  183. print(sys.argv[0], ': cannot do -t to stdout')
  184. sys.exit(1)
  185. decode(input, output)
  186. else:
  187. if options.text:
  188. if isinstance(input, str):
  189. input = open(input, 'rb')
  190. else:
  191. print(sys.argv[0], ': cannot do -t from stdin')
  192. sys.exit(1)
  193. encode(input, output)
  194. if __name__ == '__main__':
  195. test()