netarch/__init__.py

150 lines
3.0 KiB
Python
Executable File

#! /usr/bin/python
# -*- coding: utf-8 -*-
import sys
printable = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890!@#$%^&*()[]{}`~/=\\?+|\',."<> '
def unpack(fmt, buf):
"""Unpack buf based on fmt, return the rest as a string."""
size = struct.calcsize(fmt)
vals = struct.unpack(fmt, buf[:size])
return vals + (buf[size:],)
def to_printable(c):
if c in printable:
return c
elif c == '\0':
return ''
else:
return '·'
def hexdump(buf, f=sys.stdout):
"Print a hex dump of buf"
offset = 0
while buf:
s = buf[:16]
o = [('%02x' % ord(c)) for c in s] + ([' '] * (16 - len(s)))
p = [to_printable(c) for c in s]
f.write('%08x ' % offset)
f.write(' '.join(o[:8]))
f.write(' ')
f.write(' '.join(o[8:]))
f.write('')
f.write(''.join(p))
f.write('\n')
buf = buf[16:]
offset += 16
def cstring(buf):
"Return buf if buf were a C-style (NULL-terminate) string"
i = buf.index('\0')
return buf[:i]
def md5sum(txt):
return md5.new(txt).hexdigest()
def assert_equal(a, b):
assert a == b, ('%r != %r' % (a, b))
def assert_in(a, *b):
assert a in b, ('%r not in %r' % (a, b))
##
## Binary stuff
##
def bin(i):
"""Return the binary representation of i"""
r = []
while i > 0:
r.append(i % 2)
i = i >> 1
r.reverse()
s = ''.join(str(x) for x in r)
return s
class bitvector:
def __init__(self, i, length=None):
if type(i) == type(''):
self._val = 0
for c in i:
self._val <<= 8
self._val += ord(c)
if length is not None:
self._len = length
else:
self._len = len(i) * 8
else:
self._val = i
if length is not None:
self._len = length
else:
self._len = 0
while i > 0:
i >>= 1
self._len += 1
def __len__(self):
return self._len
def __getitem__(self, idx):
if idx > self._len:
raise IndexError()
idx = self._len - idx
return int((self._val >> idx) & 1)
def __getslice__(self, a, b):
if b > self._len:
b = self._len
i = self._val >> (self._len - b)
l = b - a
mask = (1 << l) - 1
return bitvector(i & mask, length=l)
def __iter__(self):
v = self._val
for i in xrange(self._len):
yield int(v & 1)
v >>= 1
def __str__(self):
r = ''
v = self._val
i = self._len
while i > 8:
o = ((v >> (i - 8)) & 0xFF)
r += chr(o)
i -= 8
if i > 0:
o = v & ((1 << i) - 1)
r += chr(o)
return r
def __int__(self):
return self._val
def __repr__(self):
l = list(self)
l.reverse()
return '<bitvector ' + ''.join(str(x) for x in l) + '>'