2 # vim: set ts=4 sts=4 sw=4 textwidth=92:
4 ################################################################################
7 # This was stolen from cfv (see http://cfv.sourceforge.net/ for a copy)
8 ################################################################################
10 import struct, errno, os
12 def get_full_filename (dir, file):
13 return os.path.abspath (os.path.expanduser (os.path.join (dir, file)))
20 def get_protected_files (dir, filename):
21 """Get all of the filenames that are protected by the par2
22 file given as the filename"""
24 full_filename = get_full_filename (dir, filename)
27 file = open(full_filename, 'rb')
29 print 'Could not open %s' % (full_filename, )
30 raise EnvironmentError, (errno.EINVAL, 'can not open par2 file')
32 pkt_header_fmt = '< 8s Q 16s 16s 16s'
33 pkt_header_size = struct.calcsize(pkt_header_fmt)
34 file_pkt_fmt = '< 16s 16s 16s Q'
35 file_pkt_size = struct.calcsize(file_pkt_fmt)
36 main_pkt_fmt = '< Q I'
37 main_pkt_size = struct.calcsize(main_pkt_fmt)
40 expected_file_ids = None
45 d = file.read(pkt_header_size)
47 raise EnvironmentError, (errno.EINVAL, 'bad par2 file')
51 magic, pkt_len, pkt_md5, set_id, pkt_type = struct.unpack(pkt_header_fmt, d)
53 if pkt_type == 'PAR 2.0\0FileDesc':
54 file_id, file_md5, file_md5_16k, file_size = \
55 struct.unpack(file_pkt_fmt, d[:file_pkt_size])
57 if seen_file_ids.get(file_id) is None:
58 seen_file_ids[file_id] = 1
59 filename = chompnulls(d[file_pkt_size:])
60 filenames.append(filename)
62 elif pkt_type == "PAR 2.0\0Main\0\0\0\0":
64 d = file.read(pkt_len - pkt_header_size)
66 raise EnvironmentError, (errno.EINVAL, 'corrupt par2 file')
68 if expected_file_ids is None:
69 expected_file_ids = []
70 slice_size, num_files = struct.unpack(main_pkt_fmt, d[:main_pkt_size])
71 num_nonrecovery = (len(d)-main_pkt_size)/16 - num_files
73 for i in range(main_pkt_size,main_pkt_size+(num_files+num_nonrecovery)*16,16):
74 expected_file_ids.append(d[i:i+16])
78 file.seek(pkt_len - pkt_header_size, 1)
79 except OverflowError, IOError:
80 raise EnvironmentError, (errno.EINVAL, 'corrupt par2 file')
82 if expected_file_ids is None:
83 raise EnvironmentError, (errno.EINVAL, \
84 "corrupt or unsupported par2 file - no main packet found")
86 for id in expected_file_ids:
87 if not seen_file_ids.has_key(id):
88 raise EnvironmentError, (errno.EINVAL, \
89 "corrupt or unsupported par2 file - " \
90 "expected file description packet not found")
97 if __name__ == '__main__':