JezK
Edit File: uu.py
# Copyright 1994 by Lance Ellinghouse # Cathedral City, California Republic, United States of America. # All Rights Reserved # Permission to use, copy, modify, and distribute this software and its # documentation for any purpose and without fee is hereby granted, # provided that the above copyright notice appear in all copies and that # both that copyright notice and this permission notice appear in # supporting documentation, and that the name of Lance Ellinghouse # not be used in advertising or publicity pertaining to distribution # of the software without specific, written prior permission. # LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO # THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND # FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE # FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT # OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. # # Modified by Jack Jansen, CWI, July 1995: # - Use binascii module to do the actual line-by-line conversion # between ascii and binary. This results in a 1000-fold speedup. The C # version is still 5 times faster, though. # - Arguments more compliant with python standard """Implementation of the UUencode and UUdecode functions. encode(in_file, out_file [,name, mode], *, backtick=False) decode(in_file [, out_file, mode, quiet]) """ import binascii import os import sys __all__ = ["Error", "encode", "decode"] class Error(Exception): pass def encode(in_file, out_file, name=None, mode=None, *, backtick=False): """Uuencode file""" # # If in_file is a pathname open it and change defaults # opened_files = [] try: if in_file == '-': in_file = sys.stdin.buffer elif isinstance(in_file, str): if name is None: name = os.path.basename(in_file) if mode is None: try: mode = os.stat(in_file).st_mode except AttributeError: pass in_file = open(in_file, 'rb') opened_files.append(in_file) # # Open out_file if it is a pathname # if out_file == '-': out_file = sys.stdout.buffer elif isinstance(out_file, str): out_file = open(out_file, 'wb') opened_files.append(out_file) # # Set defaults for name and mode # if name is None: name = '-' if mode is None: mode = 0o666 # # Remove newline chars from name # name = name.replace('\n','\\n') name = name.replace('\r','\\r') # # Write the data # out_file.write(('begin %o %s\n' % ((mode & 0o777), name)).encode("ascii")) data = in_file.read(45) while len(data) > 0: out_file.write(binascii.b2a_uu(data, backtick=backtick)) data = in_file.read(45) if backtick: out_file.write(b'`\nend\n') else: out_file.write(b' \nend\n') finally: for f in opened_files: f.close() def decode(in_file, out_file=None, mode=None, quiet=False): """Decode uuencoded file""" # # Open the input file, if needed. # opened_files = [] if in_file == '-': in_file = sys.stdin.buffer elif isinstance(in_file, str): in_file = open(in_file, 'rb') opened_files.append(in_file) try: # # Read until a begin is encountered or we've exhausted the file # while True: hdr = in_file.readline() if not hdr: raise Error('No valid begin line found in input file') if not hdr.startswith(b'begin'): continue hdrfields = hdr.split(b' ', 2) if len(hdrfields) == 3 and hdrfields[0] == b'begin': try: int(hdrfields[1], 8) break except ValueError: pass if out_file is None: # If the filename isn't ASCII, what's up with that?!? out_file = hdrfields[2].rstrip(b' \t\r\n\f').decode("ascii") if os.path.exists(out_file): raise Error(f'Cannot overwrite existing file: {out_file}') if (out_file.startswith(os.sep) or f'..{os.sep}' in out_file or ( os.altsep and (out_file.startswith(os.altsep) or f'..{os.altsep}' in out_file)) ): raise Error(f'Refusing to write to {out_file} due to directory traversal') if mode is None: mode = int(hdrfields[1], 8) # # Open the output file # if out_file == '-': out_file = sys.stdout.buffer elif isinstance(out_file, str): fp = open(out_file, 'wb') os.chmod(out_file, mode) out_file = fp opened_files.append(out_file) # # Main decoding loop # s = in_file.readline() while s and s.strip(b' \t\r\n\f') != b'end': try: data = binascii.a2b_uu(s) except binascii.Error as v: # Workaround for broken uuencoders by /Fredrik Lundh nbytes = (((s[0]-32) & 63) * 4 + 5) // 3 data = binascii.a2b_uu(s[:nbytes]) if not quiet: sys.stderr.write("Warning: %s\n" % v) out_file.write(data) s = in_file.readline() if not s: raise Error('Truncated input file') finally: for f in opened_files: f.close() def test(): """uuencode/uudecode main program""" import optparse parser = optparse.OptionParser(usage='usage: %prog [-d] [-t] [input [output]]') parser.add_option('-d', '--decode', dest='decode', help='Decode (instead of encode)?', default=False, action='store_true') parser.add_option('-t', '--text', dest='text', help='data is text, encoded format unix-compatible text?', default=False, action='store_true') (options, args) = parser.parse_args() if len(args) > 2: parser.error('incorrect number of arguments') sys.exit(1) # Use the binary streams underlying stdin/stdout input = sys.stdin.buffer output = sys.stdout.buffer if len(args) > 0: input = args[0] if len(args) > 1: output = args[1] if options.decode: if options.text: if isinstance(output, str): output = open(output, 'wb') else: print(sys.argv[0], ': cannot do -t to stdout') sys.exit(1) decode(input, output) else: if options.text: if isinstance(input, str): input = open(input, 'rb') else: print(sys.argv[0], ': cannot do -t from stdin') sys.exit(1) encode(input, output) if __name__ == '__main__': test()