Quick and dirty script to extract Quartus II .qar archives

unqar.py

# Quick and dirty script to extract Quartus II .qar archives
import os, sys, struct, zlib

buf = open(sys.argv[1], 'rb').read()

file_no = struct.unpack_from('<H', buf, 2)[0]

off = 4
for _ in range(file_no):
    (len, unk, filename_len) = struct.unpack_from('<IHH', buf, off)
    content = buf[off + 8 + filename_len:off + 8 + filename_len + len]
    if ord(buf[off + 8 + filename_len]) == 0x78 and \
       ord(buf[off + 8 + filename_len + 1]) == 0x9C:
        content = zlib.decompress(content)
    else:
        print('Not Zlib')
        assert(false)
    fn = buf[off + 8: off + 8 + filename_len]
    dest_fn = 'qar_content/' + fn
    print('Extracting {}'.format((fn)))
    try:
        os.makedirs(os.path.dirname(dest_fn))
    except OSError:
        pass
    with open(dest_fn, 'w+b') as fp:
        fp.write(content)
    off += 8 + filename_len + len