cpython/Lib/uu.py

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# 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.
# This file implements the UUencode and UUdecode functions.
# encode(filename, mode, in_file, out_file)
# decode(filename, mode, in_file)
# decode(in_file, out_file)
# decode(in_file)
# encode a single char to always be printable
def _ENC(ch):
if type(ch) == type(''):
a = ch[:1] # only 1 char
if len(a) == 0:
raise ValueError, 'need to pass in at least 1 char'
a = ord(a)
elif type(ch) == type(0):
a = ch
else:
raise TypeError, 'must pass in an integer or single character'
return chr((a & 077) + ord(' '))
# input 3 chars, output 4 encoded chars
def _outenc(str):
if len(str) > 3:
raise ValueError, 'can only accept strings of 3 chars'
p0, p1, p2 = 0, 0, 0
if len(str) > 2:
p2 = ord(str[2])
if len(str) > 1:
p1 = ord(str[1])
if len(str) > 0:
p0 = ord(str[0])
c1 = p0 >> 2
c2 = (p0 << 4) & 060 | (p1 >> 4) & 017
c3 = (p1 << 2) & 074 | (p2 >> 6) & 03
c4 = p2 & 077
rtn = _ENC(c1)
rtn = rtn + _ENC(c2)
rtn = rtn + _ENC(c3)
rtn = rtn + _ENC(c4)
return rtn
# pass in 45 bytes max, returns 62 bytes encoded
def _encode(str):
if len(str) > 45:
raise ValueError, 'cannot handle more than 45 chars at once'
length = len(str)
rtn = _ENC(length)
i = 0
while i < length:
rtn = rtn + _outenc(str[i:(i+3)])
i = i + 3
rtn = rtn + '\n'
return rtn
# encode a fileobject and write out to a file object
def encode(filename, mode, in_file, out_file):
out_file.write('begin %o %s\n' % ((mode&0777),filename))
str = in_file.read(45)
while len(str) > 0:
out_file.write(_encode(str))
str = in_file.read(45)
out_file.write(' \nend\n')
return None
# def decode a single char from printable to possibly non-printable
def _DEC(ch):
if type(ch) != type('') or len(ch) != 1:
raise ValueError, 'need to pass in a single char'
a = ord(ch[0:1])
return (a - ord(' '))
# input 4 chars encoded, output 3 chars unencoded
def _outdec(str):
if len(str) > 4:
raise ValueError, 'can only accept strings of 4 chars'
p0, p1, p2, p3 = 0, 0, 0, 0
if len(str) > 3:
p3 = _DEC(str[3])
if len(str) > 2:
p2 = _DEC(str[2])
if len(str) > 1:
p1 = _DEC(str[1])
if len(str) > 0:
p0 = _DEC(str[0])
c1 = p0 << 2 | (p1 & 060) >> 4
c2 = (p1 & 017) << 4 | (p2 & 074) >> 2
c3 = (p2 & 03) << 6 | (p3 & 077)
rtn = chr(c1)
rtn = rtn + chr(c2)
rtn = rtn + chr(c3)
return rtn
# pass in 62 bytes and return 45 bytes unencoded
def _decode(str):
if len(str) > 62:
raise ValueError, 'cannot handle more than 62 chars at once'
length = _DEC(str[0])
i = 1
rtn = ''
while len(rtn) < length:
rtn = rtn + _outdec(str[i:(i+4)])
i = i + 4
return rtn[0:length]
# decode(filename, mode, in_file)
# decode(in_file, out_file)
# decode(in_file)
def decode(*args):
ok = 1
_setup = None
out_file = None
if len(args) == 3:
filename, mode, in_file = args
if type(filename) != type(''):
ok = 0
if type(mode) != type(0):
ok = 0
try:
_ = getattr(in_file,'readline')
except AttributeError:
ok = 0
def _setup(out_file,args):
filename, mode, in_file = args
# open file as specified and assign out_file for later use
out_file = open(filename,'w',mode)
_out_file_orig = 0
_ = in_file.readline()
return (out_file,_out_file_orig)
elif len(args) == 2:
in_file, out_file = args
try:
_ = getattr(in_file,'readline')
_ = getattr(out_file,'write')
except AttributeError:
ok = 0
def _setup(out_file, args):
in_file, out_file = args
# Toss the 'begin mode filename' part.. not needed
_ = in_file.readline()
_out_file_orig = 1
return (out_file,_out_file_orig)
elif len(args) == 1:
in_file = args[0]
try:
_ = getattr(in_file,'readline')
except AttributeError:
ok = 0
def _setup(out_file, args):
import strop
in_file = args[0]
# open file as specified in uu file and
# assign out_file for later use
i = in_file.readline()
i = strop.strip(i)
if 'begin' != i[:5]:
raise IOError, 'input file not in UUencoded format'
[dummy, mode, filename] = strop.split(i)
mode = strop.atoi(mode, 8)
out_file = open(filename,'w',mode)
_out_file_orig = 0
return (out_file,_out_file_orig)
if ok != 1:
raise SyntaxError, 'must be (filename, mode, in_file) or (in_file,out_file) or (in_file)'
out_file, _out_file_orig = _setup(out_file, args)
str = in_file.readline()
while len(str) > 0 and str != ' \n' and str != 'end\n':
out_file.write(_decode(str))
str = in_file.readline()
if _out_file_orig == 0:
out_file.close()
del out_file
return None
def test():
import sys
if sys.argv[1:2] == ['-d']:
if sys.argv[2:]:
decode(open(sys.argv[2]), sys.stdout)
else:
decode(sys.stdin, sys.stdout)
elif sys.argv[1:2] == ['-e']:
if sys.argv[2:]:
file = sys.argv[2]
fp = open(file)
else:
file = '-'
fp = sys.stdin
encode(file, 0644, fp, sys.stdout)
else:
print 'usage: uu -d [file]; (to decode)'
print 'or: uu -e [file]; (to encode)'
sys.exit(2)
if __name__ == '__main__':
test()