#! /usr/bin/env python
import zipfile, zlib, binascii, struct

class FileTruncatedError(IOError):
    pass

BadZipfile = zipfile.BadZipfile


def read_one_entry(fp):
    fname = None
    def _read(size):
        data = fp.read(size)
        if len(data) < size:
            raise FileTruncatedError(fname)
        return data
    fheader = _read(4)
    if fheader == zipfile.stringCentralDir:
        return None
    if fheader != zipfile.stringFileHeader:
        raise BadZipfile, "Bad magic number %r for file header" % fheader
    fheader += _read(26)
    fheader = struct.unpack(zipfile.structFileHeader, fheader)
    fname = _read(fheader[zipfile._FH_FILENAME_LENGTH])
    _read(fheader[zipfile._FH_EXTRA_FIELD_LENGTH])
    bytes = _read(fheader[zipfile._FH_COMPRESSED_SIZE])
    ct = fheader[zipfile._FH_COMPRESSION_METHOD]
    if ct == zipfile.ZIP_STORED:
        pass
    elif ct == zipfile.ZIP_DEFLATED:
        dc = zlib.decompressobj(-15)
        bytes = dc.decompress(bytes)
        # need to feed in unused pad byte so that zlib won't choke
        ex = dc.decompress('Z') + dc.flush()
        if ex:
            bytes = bytes + ex
    else:
        raise BadZipfile, \
              "Unsupported compression method %d for file %s" % (ct, fname)
    crc = binascii.crc32(bytes)
    if crc != fheader[zipfile._FH_CRC]:
        raise BadZipfile, "Bad CRC-32 for file %s" % fname
    return fname, bytes

def enum_zip_file(file):
    if hasattr(file, 'read'):
        fp = file
        close = False
    else:
        fp = open(file, 'rb')
        close = True
    while True:
        entry = read_one_entry(fp)
        if entry is None:
            break
        yield entry
        del entry
    if close:
        fp.close()


if __name__ == '__main__':
    import sys, os
    assert len(sys.argv) == 2
    try:
        for name, data in enum_zip_file(sys.argv[1]):
            print '%10d  %s' % (len(data), name)
            if data:
                if os.path.sep in name:
                    try:
                        os.makedirs(os.path.dirname(name))
                    except OSError:
                        pass
                g = open(name, 'wb')
                g.write(data)
                g.close()
    except IOError, e:
        sys.stderr.write('%s\n' % (e,))
        sys.exit(1)