Preview: uu.py
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//opt/alt/python38/lib64/python3.8/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()
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