cpython/Lib/binhex.py

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"""binhex - Macintosh binhex compression/decompression
easy interface:
binhex(inputfilename, outputfilename)
hexbin(inputfilename, outputfilename)
"""
#
# Jack Jansen, CWI, August 1995.
#
# The module is supposed to be as compatible as possible. Especially the
# easy interface should work "as expected" on any platform.
# XXXX Note: currently, textfiles appear in mac-form on all platforms.
# We seem to lack a simple character-translate in python.
# (we should probably use ISO-Latin-1 on all but the mac platform).
# XXXX The simeple routines are too simple: they expect to hold the complete
# files in-core. Should be fixed.
# XXXX It would be nice to handle AppleDouble format on unix (for servers serving
# macs).
# XXXX I don't understand what happens when you get 0x90 times the same byte on
# input. The resulting code (xx 90 90) would appear to be interpreted as an
# escaped *value* of 0x90. All coders I've seen appear to ignore this nicety...
#
import sys
import os
import struct
import string
import binascii
DEBUG=1
testf = open('@xx', 'w') # XXXX
Error = 'binhex.Error'
# States (what have we written)
[_DID_HEADER, _DID_DATA, _DID_RSRC] = range(3)
# Various constants
REASONABLY_LARGE=32768 # Minimal amount we pass the rle-coder
LINELEN=48 # What we pass to hqx-coder at once
# *NOTE* Must be divisible by 3!
RUNCHAR=chr(0x90) # run-length introducer
#
# The code is currently byte-order dependent
if struct.pack('i', 0177) != '\0\0\0\177':
raise ImportError, 'Module binhex is big-endian only'
#
# Workarounds for non-mac machines.
if os.name == 'mac':
import macfs
def FInfo():
return macfs.FInfo()
def getfileinfo(name):
finfo = macfs.FSSpec(name).GetFInfo()
dir, file = os.path.split(name)
# XXXX Get resource/data sizes
fp = open(name, 'rb')
fp.seek(0, 2)
dlen = fp.tell()
fp = open(name, '*rb')
fp.seek(0, 2)
rlen = fp.tell()
return file, finfo, dlen, rlen
def openrsrc(name, *mode):
if mode:
mode = mode[0]
else:
mode = 'rb'
mode = '*' + mode
return open(name, mode)
else:
#
# Glue code for non-macintosh useage
#
import regsub
class FInfo:
def __init__(self):
self.Type = '????'
self.Creator = '????'
self.Flags = 0
def getfileinfo(name):
finfo = FInfo()
# Quick check for textfile
fp = open(name)
data = open(name).read(256)
for c in data:
if not c in string.whitespace and (c<' ' or ord(c) > 0177):
break
else:
finfo.Type = 'TEXT'
fp.seek(0, 2)
dsize = fp.tell()
fp.close()
dir, file = os.path.split(name)
file = regsub.sub(':', '-', file)
return file, finfo, dsize, 0
class openrsrc:
def __init__(self, *args):
pass
def read(self, *args):
return ''
def write(self, *args):
pass
def close(self):
pass
class _Hqxcoderengine:
"""Write data to the coder in 3-byte chunks"""
def __init__(self, ofp):
self.ofp = ofp
self.data = ''
def write(self, data):
self.data = self.data + data
while len(self.data) > LINELEN:
hqxdata = binascii.b2a_hqx(self.data[:LINELEN])
self.ofp.write(hqxdata+'\n')
self.data = self.data[LINELEN:]
def close(self):
if self.data:
self.ofp.write(binascii.b2a_hqx(self.data))
self.ofp.write(':\n')
self.ofp.close()
class _Rlecoderengine:
"""Write data to the RLE-coder in suitably large chunks"""
def __init__(self, ofp):
self.ofp = ofp
self.data = ''
def write(self, data):
testf.write(data) # XXXX
self.data = self.data + data
if len(self.data) < REASONABLY_LARGE:
return
rledata = binascii.rlecode_hqx(self.data)
self.ofp.write(rledata)
self.data = ''
def close(self):
if self.data:
rledata = binascii.rlecode_hqx(self.data)
self.ofp.write(rledata)
self.ofp.close()
class BinHex:
def __init__(self, (name, finfo, dlen, rlen), ofp):
if type(ofp) == type(''):
ofname = ofp
ofp = open(ofname, 'w')
if os.name == 'mac':
fss = macfs.FSSpec(ofname)
fss.SetCreatorType('BnHq', 'TEXT')
ofp.write('(This file may be decompressed with BinHex 4.0)\n\n:')
hqxer = _Hqxcoderengine(ofp)
self.ofp = _Rlecoderengine(hqxer)
self.crc = 0
if finfo == None:
finfo = FInfo()
self.dlen = dlen
self.rlen = rlen
self._writeinfo(name, finfo)
self.state = _DID_HEADER
def _writeinfo(self, name, finfo):
if DEBUG:
print 'binhex info:', name, finfo.Type, finfo.Creator, self.dlen, self.rlen
name = name
nl = len(name)
if nl > 63:
raise Error, 'Filename too long'
d = chr(nl) + name + '\0'
d2 = finfo.Type + finfo.Creator
d3 = struct.pack('h', finfo.Flags)
d4 = struct.pack('ii', self.dlen, self.rlen)
info = d + d2 + d3 + d4
self._write(info)
self._writecrc()
def _write(self, data):
self.crc = binascii.crc_hqx(data, self.crc)
self.ofp.write(data)
def _writecrc(self):
self.ofp.write(struct.pack('h', self.crc))
self.crc = 0
def write(self, data):
if self.state != _DID_HEADER:
raise Error, 'Writing data at the wrong time'
self.dlen = self.dlen - len(data)
self._write(data)
def close_data(self):
if self.dlen <> 0:
raise Error, 'Incorrect data size, diff='+`self.rlen`
self._writecrc()
self.state = _DID_DATA
def write_rsrc(self, data):
if self.state < _DID_DATA:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Writing resource data at the wrong time'
self.rlen = self.rlen - len(data)
self._write(data)
def close(self):
if self.state < _DID_DATA:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Close at the wrong time'
if self.rlen <> 0:
raise Error, "Incorrect resource-datasize, diff="+`self.rlen`
self._writecrc()
self.ofp.close()
self.state = None
def binhex(inp, out):
"""(infilename, outfilename) - Create binhex-encoded copy of a file"""
finfo = getfileinfo(inp)
ofp = BinHex(finfo, out)
ifp = open(inp, 'rb')
# XXXX Do textfile translation on non-mac systems
d = ifp.read()
ofp.write(d)
ofp.close_data()
ifp.close()
ifp = openrsrc(inp, 'rb')
d = ifp.read()
ofp.write_rsrc(d)
ofp.close()
ifp.close()
class _Hqxdecoderengine:
"""Read data via the decoder in 4-byte chunks"""
def __init__(self, ifp):
self.ifp = ifp
self.eof = 0
def read(self, wtd):
"""Read at least wtd bytes (or until EOF)"""
decdata = ''
#
# The loop here is convoluted, since we don't really now how much
# to decode: there may be newlines in the incoming data.
while wtd > 0:
if self.eof: return decdata
wtd = ((wtd+2)/3)*4
data = self.ifp.read(wtd)
#
# Next problem: there may not be a complete number of bytes in what we
# pass to a2b. Solve by yet another loop.
#
while 1:
try:
decdatacur, self.eof = binascii.a2b_hqx(data)
if self.eof: print 'EOF'
break
except binascii.Incomplete:
pass
newdata = self.ifp.read(1)
if not newdata:
raise Error, 'Premature EOF on binhex file'
data = data + newdata
decdata = decdata + decdatacur
wtd = wtd - len(decdata)
if not decdata and not self.eof:
raise Error, 'Premature EOF on binhex file'
return decdata
def close(self):
self.ifp.close()
class _Rledecoderengine:
"""Read data via the RLE-coder"""
def __init__(self, ifp):
self.ifp = ifp
self.pre_buffer = ''
self.post_buffer = ''
self.eof = 0
def read(self, wtd):
if wtd > len(self.post_buffer):
self._fill(wtd-len(self.post_buffer))
rv = self.post_buffer[:wtd]
self.post_buffer = self.post_buffer[wtd:]
print 'WTD', wtd, 'GOT', len(rv)
return rv
def _fill(self, wtd):
#
# Obfuscated code ahead. We keep at least one byte in the pre_buffer,
# so we don't stumble over an orphaned RUNCHAR later on. If the
# last or second-last char is a RUNCHAR we keep more bytes.
#
self.pre_buffer = self.pre_buffer + self.ifp.read(wtd+2)
if self.ifp.eof:
self.post_buffer = self.post_buffer + \
binascii.rledecode_hqx(self.pre_buffer)
self.pre_buffer = ''
return
lastrle = string.rfind(self.pre_buffer, RUNCHAR)
if lastrle > 0 and lastrle == len(self.pre_buffer)-1:
# Last byte is an RLE, keep two bytes
mark = len(self.pre_buffer)-2
elif lastrle > 0 and lastrle == len(self.pre_buffer)-2:
# second-last byte is an RLE. Decode all.
mark = len(self.pre_buffer)
else:
mark = len(self.pre_buffer)-1
self.post_buffer = self.post_buffer + \
binascii.rledecode_hqx(self.pre_buffer[:mark])
self.pre_buffer = self.pre_buffer[mark:]
def close(self):
self.ifp.close()
class HexBin:
def __init__(self, ifp):
if type(ifp) == type(''):
ifp = open(ifp)
#
# Find initial colon.
#
while 1:
ch = ifp.read(1)
if not ch:
raise Error, "No binhex data found"
if ch == ':':
break
if ch != '\n':
dummy = ifp.readline()
if DEBUG:
print 'SKIP:', ch+dummy
hqxifp = _Hqxdecoderengine(ifp)
self.ifp = _Rledecoderengine(hqxifp)
self.crc = 0
self._readheader()
def _read(self, len):
data = self.ifp.read(len)
self.crc = binascii.crc_hqx(data, self.crc)
return data
def _checkcrc(self):
filecrc = struct.unpack('h', self.ifp.read(2))[0] & 0xffff
self.crc = self.crc & 0xffff
if DEBUG:
print 'DBG CRC %x %x'%(self.crc, filecrc)
#if filecrc != self.crc:
# raise Error, 'CRC error, computed %x, read %x'%(self.crc, filecrc)
self.crc = 0
def _readheader(self):
len = self._read(1)
fname = self._read(ord(len))
rest = self._read(1+4+4+2+4+4)
self._checkcrc()
type = rest[1:5]
creator = rest[5:9]
flags = struct.unpack('h', rest[9:11])[0]
self.dlen = struct.unpack('l', rest[11:15])[0]
self.rlen = struct.unpack('l', rest[15:19])[0]
if DEBUG:
print 'DATA, RLEN', self.dlen, self.rlen
self.FName = fname
self.FInfo = FInfo()
self.FInfo.Creator = creator
self.FInfo.Type = type
self.FInfo.Flags = flags
self.state = _DID_HEADER
def read(self, *n):
if self.state != _DID_HEADER:
raise Error, 'Read data at wrong time'
if n:
n = n[0]
n = min(n, self.dlen)
else:
n = self.dlen
self.dlen = self.dlen - n
return self._read(n)
def close_data(self):
if self.state != _DID_HEADER:
raise Error, 'close_data at wrong time'
if self.dlen:
dummy = self._read(self.dlen)
self._checkcrc()
self.state = _DID_DATA
def read_rsrc(self, *n):
if self.state == _DID_HEADER:
self.close_data()
if self.state != _DID_DATA:
raise Error, 'Read resource data at wrong time'
if n:
n = n[0]
n = min(n, self.rlen)
else:
n = self.rlen
self.rlen = self.rlen - n
return self._read(n)
def close(self):
if self.rlen:
dummy = self.read_rsrc(self.rlen)
self._checkcrc()
self.state = _DID_RSRC
self.ifp.close()
def hexbin(inp, out):
"""(infilename, outfilename) - Decode binhexed file"""
ifp = HexBin(inp)
finfo = ifp.FInfo
if not out:
out = ifp.FName
if os.name == 'mac':
ofss = macfs.FSSpec(out)
out = ofss.as_pathname()
ofp = open(out, 'wb')
# XXXX Do translation on non-mac systems
d = ifp.read()
ofp.write(d)
ofp.close()
ifp.close_data()
d = ifp.read_rsrc()
if d:
ofp = openrsrc(out, 'wb')
ofp.write(d)
ofp.close()
if os.name == 'mac':
nfinfo = ofss.GetFInfo()
nfinfo.Creator = finfo.Creator
nfinfo.Type = finfo.Type
nfinfo.Flags = finfo.Flags
ofss.SetFInfo(nfinfo)
ifp.close()
def _test():
if os.name == 'mac':
fss, ok = macfs.StandardGetFile()
if not ok:
sys.exit(0)
fname = fss.as_pathname()
else:
fname = sys.argv[1]
#binhex(fname, fname+'.hqx')
#hexbin(fname+'.hqx', fname+'.viahqx')
hexbin(fname, fname+'.unpacked')
sys.exit(1)
if __name__ == '__main__':
_test()