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#!/usr/bin/env python
## -*- coding: utf-8 -*-
##=============================================================================
#
# Copyright (C) 2003, 2011 Alessandro Duca <alessandro.duca@gmail.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#=============================================================================
#
##=============================================================================
import os
import sys
import re
import yenc
NAME_RE = re.compile(br"^.*? name=(.+?)\r\n$")
LINE_RE = re.compile(br"^.*? line=(\d{3}) .*$")
SIZE_RE = re.compile(br"^.*? size=(\d+) .*$")
CRC32_RE = re.compile(br"^.*? crc32=(\w+)")
def main():
head_crc = trail_crc = None
if len(sys.argv) > 1:
file_in = open(sys.argv[1],"rb")
else:
try: # Python 3
file_in = sys.stdin.detach()
except: # Python < 3
file_in = sys.stdin
sys.stdin = None
with file_in:
while True:
line = file_in.readline()
if line.startswith(b"=ybegin "):
try:
name, size = NAME_RE.match(line).group(1), int(SIZE_RE.match(line).group(1))
m_obj = CRC32_RE.match(line)
if m_obj:
head_crc = m_obj.group(1)
except re.error:
sys.stderr.write("err-critical: malformed =ybegin header\n")
sys.exit(1)
break
elif not line:
sys.stderr.write("err-critical: no valid =ybegin header found\n")
sys.exit(1)
file_out = open(name,"wb")
dec = yenc.Decoder(file_out)
trailer = None
garbage = False
while True:
data = file_in.readline()
if data.startswith(b"=yend"):
trailer = data
break
elif dec.getSize() >= size:
garbage = True
else:
dec.feed(data)
dec.flush()
if trailer:
try:
size = int(SIZE_RE.match(trailer).group(1))
m_obj = CRC32_RE.search(trailer)
if m_obj:
trail_crc = m_obj.group(1)
except re.error:
sys.stderr.write("err: malformed =yend trailer\n")
else:
sys.stderr.write("warning: couldn't find =yend trailer\n")
if garbage:
sys.stderr.write("warning: garbage before =yend trailer\n")
if head_crc:
tmp_crc = head_crc.decode("ascii").lower()
elif trail_crc:
tmp_crc = trail_crc.decode("ascii").lower()
else:
sys.exit(0)
# sys.stderr.write("comparing\n")
if tmp_crc != dec.getCrc32():
sys.stderr.write("err: header: %s dec: %s CRC32 mismatch\n" % (tmp_crc,dec.getCrc32()) )
sys.exit(1)
else:
sys.exit(0)
if __name__ == "__main__":
main()
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