This page hosts a formal specification of cpio archive, old binary variant, little-endian using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.
All parsing code for Python generated by Kaitai Struct depends on the Python runtime library. You have to install it before you can parse data.
The Python runtime library can be installed from PyPI:
python3 -m pip install kaitaistructParse a local file and get structure in memory:
data = CpioOldLe.from_file("path/to/local/file.cpio")
Or parse structure from a bytes:
from kaitaistruct import KaitaiStream, BytesIO
raw = b"\x00\x01\x02..."
data = CpioOldLe(KaitaiStream(BytesIO(raw)))
After that, one can get various attributes from the structure by invoking getter methods like:
data.files # => get files
# This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild
# type: ignore
import kaitaistruct
from kaitaistruct import KaitaiStruct, KaitaiStream, BytesIO
if getattr(kaitaistruct, 'API_VERSION', (0, 9)) < (0, 11):
raise Exception("Incompatible Kaitai Struct Python API: 0.11 or later is required, but you have %s" % (kaitaistruct.__version__))
class CpioOldLe(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
super(CpioOldLe, self).__init__(_io)
self._parent = _parent
self._root = _root or self
self._read()
def _read(self):
self.files = []
i = 0
while not self._io.is_eof():
self.files.append(CpioOldLe.File(self._io, self, self._root))
i += 1
def _fetch_instances(self):
pass
for i in range(len(self.files)):
pass
self.files[i]._fetch_instances()
class File(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
super(CpioOldLe.File, self).__init__(_io)
self._parent = _parent
self._root = _root
self._read()
def _read(self):
self.header = CpioOldLe.FileHeader(self._io, self, self._root)
self.path_name = self._io.read_bytes(self.header.path_name_size - 1)
self.string_terminator = self._io.read_bytes(1)
if not self.string_terminator == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.string_terminator, self._io, u"/types/file/seq/2")
if self.header.path_name_size % 2 == 1:
pass
self.path_name_padding = self._io.read_bytes(1)
if not self.path_name_padding == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.path_name_padding, self._io, u"/types/file/seq/3")
self.file_data = self._io.read_bytes(self.header.file_size.value)
if self.header.file_size.value % 2 == 1:
pass
self.file_data_padding = self._io.read_bytes(1)
if not self.file_data_padding == b"\x00":
raise kaitaistruct.ValidationNotEqualError(b"\x00", self.file_data_padding, self._io, u"/types/file/seq/5")
if ((self.path_name == b"\x54\x52\x41\x49\x4C\x45\x52\x21\x21\x21") and (self.header.file_size.value == 0)) :
pass
self.end_of_file_padding = self._io.read_bytes_full()
def _fetch_instances(self):
pass
self.header._fetch_instances()
if self.header.path_name_size % 2 == 1:
pass
if self.header.file_size.value % 2 == 1:
pass
if ((self.path_name == b"\x54\x52\x41\x49\x4C\x45\x52\x21\x21\x21") and (self.header.file_size.value == 0)) :
pass
class FileHeader(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
super(CpioOldLe.FileHeader, self).__init__(_io)
self._parent = _parent
self._root = _root
self._read()
def _read(self):
self.magic = self._io.read_bytes(2)
if not self.magic == b"\xC7\x71":
raise kaitaistruct.ValidationNotEqualError(b"\xC7\x71", self.magic, self._io, u"/types/file_header/seq/0")
self.device_number = self._io.read_u2le()
self.inode_number = self._io.read_u2le()
self.mode = self._io.read_u2le()
self.user_id = self._io.read_u2le()
self.group_id = self._io.read_u2le()
self.number_of_links = self._io.read_u2le()
self.r_device_number = self._io.read_u2le()
self.modification_time = CpioOldLe.FourByteUnsignedInteger(self._io, self, self._root)
self.path_name_size = self._io.read_u2le()
self.file_size = CpioOldLe.FourByteUnsignedInteger(self._io, self, self._root)
def _fetch_instances(self):
pass
self.modification_time._fetch_instances()
self.file_size._fetch_instances()
class FourByteUnsignedInteger(KaitaiStruct):
def __init__(self, _io, _parent=None, _root=None):
super(CpioOldLe.FourByteUnsignedInteger, self).__init__(_io)
self._parent = _parent
self._root = _root
self._read()
def _read(self):
self.most_significant_bits = self._io.read_u2le()
self.least_significant_bits = self._io.read_u2le()
def _fetch_instances(self):
pass
@property
def value(self):
if hasattr(self, '_m_value'):
return self._m_value
self._m_value = self.least_significant_bits + (self.most_significant_bits << 16)
return getattr(self, '_m_value', None)