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cpython/Lib/tarfile.py
Johan Förberg 2b2d607095
gh-121267: Improve performance of tarfile (#121267) (#121269) 
Tarfile in the default write mode spends much of its time resolving UIDs
into usernames and GIDs into group names. By caching these mappings, a
significant speedup can be achieved.

In my simple benchmark[1], this extra caching speeds up tarfile by 8x.

[1] https://gist.github.com/jforberg/86af759c796199740c31547ae828aef2

---------

Co-authored-by: Tian Gao <gaogaotiantian@hotmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Shantanu <12621235+hauntsaninja@users.noreply.github.com>
2024-10-30 15:08:30 -07:00

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#-------------------------------------------------------------------
# tarfile.py
#-------------------------------------------------------------------
# Copyright (C) 2002 Lars Gustaebel <lars@gustaebel.de>
# All rights reserved.
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.
#
"""Read from and write to tar format archives.
"""
version = "0.9.0"
__author__ = "Lars Gust\u00e4bel (lars@gustaebel.de)"
__credits__ = "Gustavo Niemeyer, Niels Gust\u00e4bel, Richard Townsend."
#---------
# Imports
#---------
from builtins import open as bltn_open
import sys
import os
import io
import shutil
import stat
import time
import struct
import copy
import re
try:
import pwd
except ImportError:
pwd = None
try:
import grp
except ImportError:
grp = None
# os.symlink on Windows prior to 6.0 raises NotImplementedError
# OSError (winerror=1314) will be raised if the caller does not hold the
# SeCreateSymbolicLinkPrivilege privilege
symlink_exception = (AttributeError, NotImplementedError, OSError)
# from tarfile import *
__all__ = ["TarFile", "TarInfo", "is_tarfile", "TarError", "ReadError",
"CompressionError", "StreamError", "ExtractError", "HeaderError",
"ENCODING", "USTAR_FORMAT", "GNU_FORMAT", "PAX_FORMAT",
"DEFAULT_FORMAT", "open","fully_trusted_filter", "data_filter",
"tar_filter", "FilterError", "AbsoluteLinkError",
"OutsideDestinationError", "SpecialFileError", "AbsolutePathError",
"LinkOutsideDestinationError"]
#---------------------------------------------------------
# tar constants
#---------------------------------------------------------
NUL = b"\0" # the null character
BLOCKSIZE = 512 # length of processing blocks
RECORDSIZE = BLOCKSIZE * 20 # length of records
GNU_MAGIC = b"ustar \0" # magic gnu tar string
POSIX_MAGIC = b"ustar\x0000" # magic posix tar string
LENGTH_NAME = 100 # maximum length of a filename
LENGTH_LINK = 100 # maximum length of a linkname
LENGTH_PREFIX = 155 # maximum length of the prefix field
REGTYPE = b"0" # regular file
AREGTYPE = b"\0" # regular file
LNKTYPE = b"1" # link (inside tarfile)
SYMTYPE = b"2" # symbolic link
CHRTYPE = b"3" # character special device
BLKTYPE = b"4" # block special device
DIRTYPE = b"5" # directory
FIFOTYPE = b"6" # fifo special device
CONTTYPE = b"7" # contiguous file
GNUTYPE_LONGNAME = b"L" # GNU tar longname
GNUTYPE_LONGLINK = b"K" # GNU tar longlink
GNUTYPE_SPARSE = b"S" # GNU tar sparse file
XHDTYPE = b"x" # POSIX.1-2001 extended header
XGLTYPE = b"g" # POSIX.1-2001 global header
SOLARIS_XHDTYPE = b"X" # Solaris extended header
USTAR_FORMAT = 0 # POSIX.1-1988 (ustar) format
GNU_FORMAT = 1 # GNU tar format
PAX_FORMAT = 2 # POSIX.1-2001 (pax) format
DEFAULT_FORMAT = PAX_FORMAT
#---------------------------------------------------------
# tarfile constants
#---------------------------------------------------------
# File types that tarfile supports:
SUPPORTED_TYPES = (REGTYPE, AREGTYPE, LNKTYPE,
SYMTYPE, DIRTYPE, FIFOTYPE,
CONTTYPE, CHRTYPE, BLKTYPE,
GNUTYPE_LONGNAME, GNUTYPE_LONGLINK,
GNUTYPE_SPARSE)
# File types that will be treated as a regular file.
REGULAR_TYPES = (REGTYPE, AREGTYPE,
CONTTYPE, GNUTYPE_SPARSE)
# File types that are part of the GNU tar format.
GNU_TYPES = (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK,
GNUTYPE_SPARSE)
# Fields from a pax header that override a TarInfo attribute.
PAX_FIELDS = ("path", "linkpath", "size", "mtime",
"uid", "gid", "uname", "gname")
# Fields from a pax header that are affected by hdrcharset.
PAX_NAME_FIELDS = {"path", "linkpath", "uname", "gname"}
# Fields in a pax header that are numbers, all other fields
# are treated as strings.
PAX_NUMBER_FIELDS = {
"atime": float,
"ctime": float,
"mtime": float,
"uid": int,
"gid": int,
"size": int
}
#---------------------------------------------------------
# initialization
#---------------------------------------------------------
if os.name == "nt":
ENCODING = "utf-8"
else:
ENCODING = sys.getfilesystemencoding()
#---------------------------------------------------------
# Some useful functions
#---------------------------------------------------------
def stn(s, length, encoding, errors):
"""Convert a string to a null-terminated bytes object.
"""
if s is None:
raise ValueError("metadata cannot contain None")
s = s.encode(encoding, errors)
return s[:length] + (length - len(s)) * NUL
def nts(s, encoding, errors):
"""Convert a null-terminated bytes object to a string.
"""
p = s.find(b"\0")
if p != -1:
s = s[:p]
return s.decode(encoding, errors)
def nti(s):
"""Convert a number field to a python number.
"""
# There are two possible encodings for a number field, see
# itn() below.
if s[0] in (0o200, 0o377):
n = 0
for i in range(len(s) - 1):
n <<= 8
n += s[i + 1]
if s[0] == 0o377:
n = -(256 ** (len(s) - 1) - n)
else:
try:
s = nts(s, "ascii", "strict")
n = int(s.strip() or "0", 8)
except ValueError:
raise InvalidHeaderError("invalid header")
return n
def itn(n, digits=8, format=DEFAULT_FORMAT):
"""Convert a python number to a number field.
"""
# POSIX 1003.1-1988 requires numbers to be encoded as a string of
# octal digits followed by a null-byte, this allows values up to
# (8**(digits-1))-1. GNU tar allows storing numbers greater than
# that if necessary. A leading 0o200 or 0o377 byte indicate this
# particular encoding, the following digits-1 bytes are a big-endian
# base-256 representation. This allows values up to (256**(digits-1))-1.
# A 0o200 byte indicates a positive number, a 0o377 byte a negative
# number.
original_n = n
n = int(n)
if 0 <= n < 8 ** (digits - 1):
s = bytes("%0*o" % (digits - 1, n), "ascii") + NUL
elif format == GNU_FORMAT and -256 ** (digits - 1) <= n < 256 ** (digits - 1):
if n >= 0:
s = bytearray([0o200])
else:
s = bytearray([0o377])
n = 256 ** digits + n
for i in range(digits - 1):
s.insert(1, n & 0o377)
n >>= 8
else:
raise ValueError("overflow in number field")
return s
def calc_chksums(buf):
"""Calculate the checksum for a member's header by summing up all
characters except for the chksum field which is treated as if
it was filled with spaces. According to the GNU tar sources,
some tars (Sun and NeXT) calculate chksum with signed char,
which will be different if there are chars in the buffer with
the high bit set. So we calculate two checksums, unsigned and
signed.
"""
unsigned_chksum = 256 + sum(struct.unpack_from("148B8x356B", buf))
signed_chksum = 256 + sum(struct.unpack_from("148b8x356b", buf))
return unsigned_chksum, signed_chksum
def copyfileobj(src, dst, length=None, exception=OSError, bufsize=None):
"""Copy length bytes from fileobj src to fileobj dst.
If length is None, copy the entire content.
"""
bufsize = bufsize or 16 * 1024
if length == 0:
return
if length is None:
shutil.copyfileobj(src, dst, bufsize)
return
blocks, remainder = divmod(length, bufsize)
for b in range(blocks):
buf = src.read(bufsize)
if len(buf) < bufsize:
raise exception("unexpected end of data")
dst.write(buf)
if remainder != 0:
buf = src.read(remainder)
if len(buf) < remainder:
raise exception("unexpected end of data")
dst.write(buf)
return
def _safe_print(s):
encoding = getattr(sys.stdout, 'encoding', None)
if encoding is not None:
s = s.encode(encoding, 'backslashreplace').decode(encoding)
print(s, end=' ')
class TarError(Exception):
"""Base exception."""
pass
class ExtractError(TarError):
"""General exception for extract errors."""
pass
class ReadError(TarError):
"""Exception for unreadable tar archives."""
pass
class CompressionError(TarError):
"""Exception for unavailable compression methods."""
pass
class StreamError(TarError):
"""Exception for unsupported operations on stream-like TarFiles."""
pass
class HeaderError(TarError):
"""Base exception for header errors."""
pass
class EmptyHeaderError(HeaderError):
"""Exception for empty headers."""
pass
class TruncatedHeaderError(HeaderError):
"""Exception for truncated headers."""
pass
class EOFHeaderError(HeaderError):
"""Exception for end of file headers."""
pass
class InvalidHeaderError(HeaderError):
"""Exception for invalid headers."""
pass
class SubsequentHeaderError(HeaderError):
"""Exception for missing and invalid extended headers."""
pass
#---------------------------
# internal stream interface
#---------------------------
class _LowLevelFile:
"""Low-level file object. Supports reading and writing.
It is used instead of a regular file object for streaming
access.
"""
def __init__(self, name, mode):
mode = {
"r": os.O_RDONLY,
"w": os.O_WRONLY | os.O_CREAT | os.O_TRUNC,
}[mode]
if hasattr(os, "O_BINARY"):
mode |= os.O_BINARY
self.fd = os.open(name, mode, 0o666)
def close(self):
os.close(self.fd)
def read(self, size):
return os.read(self.fd, size)
def write(self, s):
os.write(self.fd, s)
class _Stream:
"""Class that serves as an adapter between TarFile and
a stream-like object. The stream-like object only
needs to have a read() or write() method that works with bytes,
and the method is accessed blockwise.
Use of gzip or bzip2 compression is possible.
A stream-like object could be for example: sys.stdin.buffer,
sys.stdout.buffer, a socket, a tape device etc.
_Stream is intended to be used only internally.
"""
def __init__(self, name, mode, comptype, fileobj, bufsize,
compresslevel):
"""Construct a _Stream object.
"""
self._extfileobj = True
if fileobj is None:
fileobj = _LowLevelFile(name, mode)
self._extfileobj = False
if comptype == '*':
# Enable transparent compression detection for the
# stream interface
fileobj = _StreamProxy(fileobj)
comptype = fileobj.getcomptype()
self.name = name or ""
self.mode = mode
self.comptype = comptype
self.fileobj = fileobj
self.bufsize = bufsize
self.buf = b""
self.pos = 0
self.closed = False
try:
if comptype == "gz":
try:
import zlib
except ImportError:
raise CompressionError("zlib module is not available") from None
self.zlib = zlib
self.crc = zlib.crc32(b"")
if mode == "r":
self.exception = zlib.error
self._init_read_gz()
else:
self._init_write_gz(compresslevel)
elif comptype == "bz2":
try:
import bz2
except ImportError:
raise CompressionError("bz2 module is not available") from None
if mode == "r":
self.dbuf = b""
self.cmp = bz2.BZ2Decompressor()
self.exception = OSError
else:
self.cmp = bz2.BZ2Compressor(compresslevel)
elif comptype == "xz":
try:
import lzma
except ImportError:
raise CompressionError("lzma module is not available") from None
if mode == "r":
self.dbuf = b""
self.cmp = lzma.LZMADecompressor()
self.exception = lzma.LZMAError
else:
self.cmp = lzma.LZMACompressor()
elif comptype != "tar":
raise CompressionError("unknown compression type %r" % comptype)
except:
if not self._extfileobj:
self.fileobj.close()
self.closed = True
raise
def __del__(self):
if hasattr(self, "closed") and not self.closed:
self.close()
def _init_write_gz(self, compresslevel):
"""Initialize for writing with gzip compression.
"""
self.cmp = self.zlib.compressobj(compresslevel,
self.zlib.DEFLATED,
-self.zlib.MAX_WBITS,
self.zlib.DEF_MEM_LEVEL,
0)
timestamp = struct.pack("<L", int(time.time()))
self.__write(b"\037\213\010\010" + timestamp + b"\002\377")
if self.name.endswith(".gz"):
self.name = self.name[:-3]
# Honor "directory components removed" from RFC1952
self.name = os.path.basename(self.name)
# RFC1952 says we must use ISO-8859-1 for the FNAME field.
self.__write(self.name.encode("iso-8859-1", "replace") + NUL)
def write(self, s):
"""Write string s to the stream.
"""
if self.comptype == "gz":
self.crc = self.zlib.crc32(s, self.crc)
self.pos += len(s)
if self.comptype != "tar":
s = self.cmp.compress(s)
self.__write(s)
def __write(self, s):
"""Write string s to the stream if a whole new block
is ready to be written.
"""
self.buf += s
while len(self.buf) > self.bufsize:
self.fileobj.write(self.buf[:self.bufsize])
self.buf = self.buf[self.bufsize:]
def close(self):
"""Close the _Stream object. No operation should be
done on it afterwards.
"""
if self.closed:
return
self.closed = True
try:
if self.mode == "w" and self.comptype != "tar":
self.buf += self.cmp.flush()
if self.mode == "w" and self.buf:
self.fileobj.write(self.buf)
self.buf = b""
if self.comptype == "gz":
self.fileobj.write(struct.pack("<L", self.crc))
self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFF))
finally:
if not self._extfileobj:
self.fileobj.close()
def _init_read_gz(self):
"""Initialize for reading a gzip compressed fileobj.
"""
self.cmp = self.zlib.decompressobj(-self.zlib.MAX_WBITS)
self.dbuf = b""
# taken from gzip.GzipFile with some alterations
if self.__read(2) != b"\037\213":
raise ReadError("not a gzip file")
if self.__read(1) != b"\010":
raise CompressionError("unsupported compression method")
flag = ord(self.__read(1))
self.__read(6)
if flag & 4:
xlen = ord(self.__read(1)) + 256 * ord(self.__read(1))
self.read(xlen)
if flag & 8:
while True:
s = self.__read(1)
if not s or s == NUL:
break
if flag & 16:
while True:
s = self.__read(1)
if not s or s == NUL:
break
if flag & 2:
self.__read(2)
def tell(self):
"""Return the stream's file pointer position.
"""
return self.pos
def seek(self, pos=0):
"""Set the stream's file pointer to pos. Negative seeking
is forbidden.
"""
if pos - self.pos >= 0:
blocks, remainder = divmod(pos - self.pos, self.bufsize)
for i in range(blocks):
self.read(self.bufsize)
self.read(remainder)
else:
raise StreamError("seeking backwards is not allowed")
return self.pos
def read(self, size):
"""Return the next size number of bytes from the stream."""
assert size is not None
buf = self._read(size)
self.pos += len(buf)
return buf
def _read(self, size):
"""Return size bytes from the stream.
"""
if self.comptype == "tar":
return self.__read(size)
c = len(self.dbuf)
t = [self.dbuf]
while c < size:
# Skip underlying buffer to avoid unaligned double buffering.
if self.buf:
buf = self.buf
self.buf = b""
else:
buf = self.fileobj.read(self.bufsize)
if not buf:
break
try:
buf = self.cmp.decompress(buf)
except self.exception as e:
raise ReadError("invalid compressed data") from e
t.append(buf)
c += len(buf)
t = b"".join(t)
self.dbuf = t[size:]
return t[:size]
def __read(self, size):
"""Return size bytes from stream. If internal buffer is empty,
read another block from the stream.
"""
c = len(self.buf)
t = [self.buf]
while c < size:
buf = self.fileobj.read(self.bufsize)
if not buf:
break
t.append(buf)
c += len(buf)
t = b"".join(t)
self.buf = t[size:]
return t[:size]
# class _Stream
class _StreamProxy(object):
"""Small proxy class that enables transparent compression
detection for the Stream interface (mode 'r|*').
"""
def __init__(self, fileobj):
self.fileobj = fileobj
self.buf = self.fileobj.read(BLOCKSIZE)
def read(self, size):
self.read = self.fileobj.read
return self.buf
def getcomptype(self):
if self.buf.startswith(b"\x1f\x8b\x08"):
return "gz"
elif self.buf[0:3] == b"BZh" and self.buf[4:10] == b"1AY&SY":
return "bz2"
elif self.buf.startswith((b"\x5d\x00\x00\x80", b"\xfd7zXZ")):
return "xz"
else:
return "tar"
def close(self):
self.fileobj.close()
# class StreamProxy
#------------------------
# Extraction file object
#------------------------
class _FileInFile(object):
"""A thin wrapper around an existing file object that
provides a part of its data as an individual file
object.
"""
def __init__(self, fileobj, offset, size, name, blockinfo=None):
self.fileobj = fileobj
self.offset = offset
self.size = size
self.position = 0
self.name = name
self.closed = False
if blockinfo is None:
blockinfo = [(0, size)]
# Construct a map with data and zero blocks.
self.map_index = 0
self.map = []
lastpos = 0
realpos = self.offset
for offset, size in blockinfo:
if offset > lastpos:
self.map.append((False, lastpos, offset, None))
self.map.append((True, offset, offset + size, realpos))
realpos += size
lastpos = offset + size
if lastpos < self.size:
self.map.append((False, lastpos, self.size, None))
def flush(self):
pass
@property
def mode(self):
return 'rb'
def readable(self):
return True
def writable(self):
return False
def seekable(self):
return self.fileobj.seekable()
def tell(self):
"""Return the current file position.
"""
return self.position
def seek(self, position, whence=io.SEEK_SET):
"""Seek to a position in the file.
"""
if whence == io.SEEK_SET:
self.position = min(max(position, 0), self.size)
elif whence == io.SEEK_CUR:
if position < 0:
self.position = max(self.position + position, 0)
else:
self.position = min(self.position + position, self.size)
elif whence == io.SEEK_END:
self.position = max(min(self.size + position, self.size), 0)
else:
raise ValueError("Invalid argument")
return self.position
def read(self, size=None):
"""Read data from the file.
"""
if size is None:
size = self.size - self.position
else:
size = min(size, self.size - self.position)
buf = b""
while size > 0:
while True:
data, start, stop, offset = self.map[self.map_index]
if start <= self.position < stop:
break
else:
self.map_index += 1
if self.map_index == len(self.map):
self.map_index = 0
length = min(size, stop - self.position)
if data:
self.fileobj.seek(offset + (self.position - start))
b = self.fileobj.read(length)
if len(b) != length:
raise ReadError("unexpected end of data")
buf += b
else:
buf += NUL * length
size -= length
self.position += length
return buf
def readinto(self, b):
buf = self.read(len(b))
b[:len(buf)] = buf
return len(buf)
def close(self):
self.closed = True
#class _FileInFile
class ExFileObject(io.BufferedReader):
def __init__(self, tarfile, tarinfo):
fileobj = _FileInFile(tarfile.fileobj, tarinfo.offset_data,
tarinfo.size, tarinfo.name, tarinfo.sparse)
super().__init__(fileobj)
#class ExFileObject
#-----------------------------
# extraction filters (PEP 706)
#-----------------------------
class FilterError(TarError):
pass
class AbsolutePathError(FilterError):
def __init__(self, tarinfo):
self.tarinfo = tarinfo
super().__init__(f'member {tarinfo.name!r} has an absolute path')
class OutsideDestinationError(FilterError):
def __init__(self, tarinfo, path):
self.tarinfo = tarinfo
self._path = path
super().__init__(f'{tarinfo.name!r} would be extracted to {path!r}, '
+ 'which is outside the destination')
class SpecialFileError(FilterError):
def __init__(self, tarinfo):
self.tarinfo = tarinfo
super().__init__(f'{tarinfo.name!r} is a special file')
class AbsoluteLinkError(FilterError):
def __init__(self, tarinfo):
self.tarinfo = tarinfo
super().__init__(f'{tarinfo.name!r} is a link to an absolute path')
class LinkOutsideDestinationError(FilterError):
def __init__(self, tarinfo, path):
self.tarinfo = tarinfo
self._path = path
super().__init__(f'{tarinfo.name!r} would link to {path!r}, '
+ 'which is outside the destination')
def _get_filtered_attrs(member, dest_path, for_data=True):
new_attrs = {}
name = member.name
dest_path = os.path.realpath(dest_path)
# Strip leading / (tar's directory separator) from filenames.
# Include os.sep (target OS directory separator) as well.
if name.startswith(('/', os.sep)):
name = new_attrs['name'] = member.path.lstrip('/' + os.sep)
if os.path.isabs(name):
# Path is absolute even after stripping.
# For example, 'C:/foo' on Windows.
raise AbsolutePathError(member)
# Ensure we stay in the destination
target_path = os.path.realpath(os.path.join(dest_path, name))
if os.path.commonpath([target_path, dest_path]) != dest_path:
raise OutsideDestinationError(member, target_path)
# Limit permissions (no high bits, and go-w)
mode = member.mode
if mode is not None:
# Strip high bits & group/other write bits
mode = mode & 0o755
if for_data:
# For data, handle permissions & file types
if member.isreg() or member.islnk():
if not mode & 0o100:
# Clear executable bits if not executable by user
mode &= ~0o111
# Ensure owner can read & write
mode |= 0o600
elif member.isdir() or member.issym():
# Ignore mode for directories & symlinks
mode = None
else:
# Reject special files
raise SpecialFileError(member)
if mode != member.mode:
new_attrs['mode'] = mode
if for_data:
# Ignore ownership for 'data'
if member.uid is not None:
new_attrs['uid'] = None
if member.gid is not None:
new_attrs['gid'] = None
if member.uname is not None:
new_attrs['uname'] = None
if member.gname is not None:
new_attrs['gname'] = None
# Check link destination for 'data'
if member.islnk() or member.issym():
if os.path.isabs(member.linkname):
raise AbsoluteLinkError(member)
if member.issym():
target_path = os.path.join(dest_path,
os.path.dirname(name),
member.linkname)
else:
target_path = os.path.join(dest_path,
member.linkname)
target_path = os.path.realpath(target_path)
if os.path.commonpath([target_path, dest_path]) != dest_path:
raise LinkOutsideDestinationError(member, target_path)
return new_attrs
def fully_trusted_filter(member, dest_path):
return member
def tar_filter(member, dest_path):
new_attrs = _get_filtered_attrs(member, dest_path, False)
if new_attrs:
return member.replace(**new_attrs, deep=False)
return member
def data_filter(member, dest_path):
new_attrs = _get_filtered_attrs(member, dest_path, True)
if new_attrs:
return member.replace(**new_attrs, deep=False)
return member
_NAMED_FILTERS = {
"fully_trusted": fully_trusted_filter,
"tar": tar_filter,
"data": data_filter,
}
#------------------
# Exported Classes
#------------------
# Sentinel for replace() defaults, meaning "don't change the attribute"
_KEEP = object()
# Header length is digits followed by a space.
_header_length_prefix_re = re.compile(br"([0-9]{1,20}) ")
class TarInfo(object):
"""Informational class which holds the details about an
archive member given by a tar header block.
TarInfo objects are returned by TarFile.getmember(),
TarFile.getmembers() and TarFile.gettarinfo() and are
usually created internally.
"""
__slots__ = dict(
name = 'Name of the archive member.',
mode = 'Permission bits.',
uid = 'User ID of the user who originally stored this member.',
gid = 'Group ID of the user who originally stored this member.',
size = 'Size in bytes.',
mtime = 'Time of last modification.',
chksum = 'Header checksum.',
type = ('File type. type is usually one of these constants: '
'REGTYPE, AREGTYPE, LNKTYPE, SYMTYPE, DIRTYPE, FIFOTYPE, '
'CONTTYPE, CHRTYPE, BLKTYPE, GNUTYPE_SPARSE.'),
linkname = ('Name of the target file name, which is only present '
'in TarInfo objects of type LNKTYPE and SYMTYPE.'),
uname = 'User name.',
gname = 'Group name.',
devmajor = 'Device major number.',
devminor = 'Device minor number.',
offset = 'The tar header starts here.',
offset_data = "The file's data starts here.",
pax_headers = ('A dictionary containing key-value pairs of an '
'associated pax extended header.'),
sparse = 'Sparse member information.',
_tarfile = None,
_sparse_structs = None,
_link_target = None,
)
def __init__(self, name=""):
"""Construct a TarInfo object. name is the optional name
of the member.
"""
self.name = name # member name
self.mode = 0o644 # file permissions
self.uid = 0 # user id
self.gid = 0 # group id
self.size = 0 # file size
self.mtime = 0 # modification time
self.chksum = 0 # header checksum
self.type = REGTYPE # member type
self.linkname = "" # link name
self.uname = "" # user name
self.gname = "" # group name
self.devmajor = 0 # device major number
self.devminor = 0 # device minor number
self.offset = 0 # the tar header starts here
self.offset_data = 0 # the file's data starts here
self.sparse = None # sparse member information
self.pax_headers = {} # pax header information
@property
def tarfile(self):
import warnings
warnings.warn(
'The undocumented "tarfile" attribute of TarInfo objects '
+ 'is deprecated and will be removed in Python 3.16',
DeprecationWarning, stacklevel=2)
return self._tarfile
@tarfile.setter
def tarfile(self, tarfile):
import warnings
warnings.warn(
'The undocumented "tarfile" attribute of TarInfo objects '
+ 'is deprecated and will be removed in Python 3.16',
DeprecationWarning, stacklevel=2)
self._tarfile = tarfile
@property
def path(self):
'In pax headers, "name" is called "path".'
return self.name
@path.setter
def path(self, name):
self.name = name
@property
def linkpath(self):
'In pax headers, "linkname" is called "linkpath".'
return self.linkname
@linkpath.setter
def linkpath(self, linkname):
self.linkname = linkname
def __repr__(self):
return "<%s %r at %#x>" % (self.__class__.__name__,self.name,id(self))
def replace(self, *,
name=_KEEP, mtime=_KEEP, mode=_KEEP, linkname=_KEEP,
uid=_KEEP, gid=_KEEP, uname=_KEEP, gname=_KEEP,
deep=True, _KEEP=_KEEP):
"""Return a deep copy of self with the given attributes replaced.
"""
if deep:
result = copy.deepcopy(self)
else:
result = copy.copy(self)
if name is not _KEEP:
result.name = name
if mtime is not _KEEP:
result.mtime = mtime
if mode is not _KEEP:
result.mode = mode
if linkname is not _KEEP:
result.linkname = linkname
if uid is not _KEEP:
result.uid = uid
if gid is not _KEEP:
result.gid = gid
if uname is not _KEEP:
result.uname = uname
if gname is not _KEEP:
result.gname = gname
return result
def get_info(self):
"""Return the TarInfo's attributes as a dictionary.
"""
if self.mode is None:
mode = None
else:
mode = self.mode & 0o7777
info = {
"name": self.name,
"mode": mode,
"uid": self.uid,
"gid": self.gid,
"size": self.size,
"mtime": self.mtime,
"chksum": self.chksum,
"type": self.type,
"linkname": self.linkname,
"uname": self.uname,
"gname": self.gname,
"devmajor": self.devmajor,
"devminor": self.devminor
}
if info["type"] == DIRTYPE and not info["name"].endswith("/"):
info["name"] += "/"
return info
def tobuf(self, format=DEFAULT_FORMAT, encoding=ENCODING, errors="surrogateescape"):
"""Return a tar header as a string of 512 byte blocks.
"""
info = self.get_info()
for name, value in info.items():
if value is None:
raise ValueError("%s may not be None" % name)
if format == USTAR_FORMAT:
return self.create_ustar_header(info, encoding, errors)
elif format == GNU_FORMAT:
return self.create_gnu_header(info, encoding, errors)
elif format == PAX_FORMAT:
return self.create_pax_header(info, encoding)
else:
raise ValueError("invalid format")
def create_ustar_header(self, info, encoding, errors):
"""Return the object as a ustar header block.
"""
info["magic"] = POSIX_MAGIC
if len(info["linkname"].encode(encoding, errors)) > LENGTH_LINK:
raise ValueError("linkname is too long")
if len(info["name"].encode(encoding, errors)) > LENGTH_NAME:
info["prefix"], info["name"] = self._posix_split_name(info["name"], encoding, errors)
return self._create_header(info, USTAR_FORMAT, encoding, errors)
def create_gnu_header(self, info, encoding, errors):
"""Return the object as a GNU header block sequence.
"""
info["magic"] = GNU_MAGIC
buf = b""
if len(info["linkname"].encode(encoding, errors)) > LENGTH_LINK:
buf += self._create_gnu_long_header(info["linkname"], GNUTYPE_LONGLINK, encoding, errors)
if len(info["name"].encode(encoding, errors)) > LENGTH_NAME:
buf += self._create_gnu_long_header(info["name"], GNUTYPE_LONGNAME, encoding, errors)
return buf + self._create_header(info, GNU_FORMAT, encoding, errors)
def create_pax_header(self, info, encoding):
"""Return the object as a ustar header block. If it cannot be
represented this way, prepend a pax extended header sequence
with supplement information.
"""
info["magic"] = POSIX_MAGIC
pax_headers = self.pax_headers.copy()
# Test string fields for values that exceed the field length or cannot
# be represented in ASCII encoding.
for name, hname, length in (
("name", "path", LENGTH_NAME), ("linkname", "linkpath", LENGTH_LINK),
("uname", "uname", 32), ("gname", "gname", 32)):
if hname in pax_headers:
# The pax header has priority.
continue
# Try to encode the string as ASCII.
try:
info[name].encode("ascii", "strict")
except UnicodeEncodeError:
pax_headers[hname] = info[name]
continue
if len(info[name]) > length:
pax_headers[hname] = info[name]
# Test number fields for values that exceed the field limit or values
# that like to be stored as float.
for name, digits in (("uid", 8), ("gid", 8), ("size", 12), ("mtime", 12)):
needs_pax = False
val = info[name]
val_is_float = isinstance(val, float)
val_int = round(val) if val_is_float else val
if not 0 <= val_int < 8 ** (digits - 1):
# Avoid overflow.
info[name] = 0
needs_pax = True
elif val_is_float:
# Put rounded value in ustar header, and full
# precision value in pax header.
info[name] = val_int
needs_pax = True
# The existing pax header has priority.
if needs_pax and name not in pax_headers:
pax_headers[name] = str(val)
# Create a pax extended header if necessary.
if pax_headers:
buf = self._create_pax_generic_header(pax_headers, XHDTYPE, encoding)
else:
buf = b""
return buf + self._create_header(info, USTAR_FORMAT, "ascii", "replace")
@classmethod
def create_pax_global_header(cls, pax_headers):
"""Return the object as a pax global header block sequence.
"""
return cls._create_pax_generic_header(pax_headers, XGLTYPE, "utf-8")
def _posix_split_name(self, name, encoding, errors):
"""Split a name longer than 100 chars into a prefix
and a name part.
"""
components = name.split("/")
for i in range(1, len(components)):
prefix = "/".join(components[:i])
name = "/".join(components[i:])
if len(prefix.encode(encoding, errors)) <= LENGTH_PREFIX and \
len(name.encode(encoding, errors)) <= LENGTH_NAME:
break
else:
raise ValueError("name is too long")
return prefix, name
@staticmethod
def _create_header(info, format, encoding, errors):
"""Return a header block. info is a dictionary with file
information, format must be one of the *_FORMAT constants.
"""
has_device_fields = info.get("type") in (CHRTYPE, BLKTYPE)
if has_device_fields:
devmajor = itn(info.get("devmajor", 0), 8, format)
devminor = itn(info.get("devminor", 0), 8, format)
else:
devmajor = stn("", 8, encoding, errors)
devminor = stn("", 8, encoding, errors)
# None values in metadata should cause ValueError.
# itn()/stn() do this for all fields except type.
filetype = info.get("type", REGTYPE)
if filetype is None:
raise ValueError("TarInfo.type must not be None")
parts = [
stn(info.get("name", ""), 100, encoding, errors),
itn(info.get("mode", 0) & 0o7777, 8, format),
itn(info.get("uid", 0), 8, format),
itn(info.get("gid", 0), 8, format),
itn(info.get("size", 0), 12, format),
itn(info.get("mtime", 0), 12, format),
b" ", # checksum field
filetype,
stn(info.get("linkname", ""), 100, encoding, errors),
info.get("magic", POSIX_MAGIC),
stn(info.get("uname", ""), 32, encoding, errors),
stn(info.get("gname", ""), 32, encoding, errors),
devmajor,
devminor,
stn(info.get("prefix", ""), 155, encoding, errors)
]
buf = struct.pack("%ds" % BLOCKSIZE, b"".join(parts))
chksum = calc_chksums(buf[-BLOCKSIZE:])[0]
buf = buf[:-364] + bytes("%06o\0" % chksum, "ascii") + buf[-357:]
return buf
@staticmethod
def _create_payload(payload):
"""Return the string payload filled with zero bytes
up to the next 512 byte border.
"""
blocks, remainder = divmod(len(payload), BLOCKSIZE)
if remainder > 0:
payload += (BLOCKSIZE - remainder) * NUL
return payload
@classmethod
def _create_gnu_long_header(cls, name, type, encoding, errors):
"""Return a GNUTYPE_LONGNAME or GNUTYPE_LONGLINK sequence
for name.
"""
name = name.encode(encoding, errors) + NUL
info = {}
info["name"] = "././@LongLink"
info["type"] = type
info["size"] = len(name)
info["magic"] = GNU_MAGIC
# create extended header + name blocks.
return cls._create_header(info, USTAR_FORMAT, encoding, errors) + \
cls._create_payload(name)
@classmethod
def _create_pax_generic_header(cls, pax_headers, type, encoding):
"""Return a POSIX.1-2008 extended or global header sequence
that contains a list of keyword, value pairs. The values
must be strings.
"""
# Check if one of the fields contains surrogate characters and thereby
# forces hdrcharset=BINARY, see _proc_pax() for more information.
binary = False
for keyword, value in pax_headers.items():
try:
value.encode("utf-8", "strict")
except UnicodeEncodeError:
binary = True
break
records = b""
if binary:
# Put the hdrcharset field at the beginning of the header.
records += b"21 hdrcharset=BINARY\n"
for keyword, value in pax_headers.items():
keyword = keyword.encode("utf-8")
if binary:
# Try to restore the original byte representation of 'value'.
# Needless to say, that the encoding must match the string.
value = value.encode(encoding, "surrogateescape")
else:
value = value.encode("utf-8")
l = len(keyword) + len(value) + 3 # ' ' + '=' + '\n'
n = p = 0
while True:
n = l + len(str(p))
if n == p:
break
p = n
records += bytes(str(p), "ascii") + b" " + keyword + b"=" + value + b"\n"
# We use a hardcoded "././@PaxHeader" name like star does
# instead of the one that POSIX recommends.
info = {}
info["name"] = "././@PaxHeader"
info["type"] = type
info["size"] = len(records)
info["magic"] = POSIX_MAGIC
# Create pax header + record blocks.
return cls._create_header(info, USTAR_FORMAT, "ascii", "replace") + \
cls._create_payload(records)
@classmethod
def frombuf(cls, buf, encoding, errors):
"""Construct a TarInfo object from a 512 byte bytes object.
"""
if len(buf) == 0:
raise EmptyHeaderError("empty header")
if len(buf) != BLOCKSIZE:
raise TruncatedHeaderError("truncated header")
if buf.count(NUL) == BLOCKSIZE:
raise EOFHeaderError("end of file header")
chksum = nti(buf[148:156])
if chksum not in calc_chksums(buf):
raise InvalidHeaderError("bad checksum")
obj = cls()
obj.name = nts(buf[0:100], encoding, errors)
obj.mode = nti(buf[100:108])
obj.uid = nti(buf[108:116])
obj.gid = nti(buf[116:124])
obj.size = nti(buf[124:136])
obj.mtime = nti(buf[136:148])
obj.chksum = chksum
obj.type = buf[156:157]
obj.linkname = nts(buf[157:257], encoding, errors)
obj.uname = nts(buf[265:297], encoding, errors)
obj.gname = nts(buf[297:329], encoding, errors)
obj.devmajor = nti(buf[329:337])
obj.devminor = nti(buf[337:345])
prefix = nts(buf[345:500], encoding, errors)
# Old V7 tar format represents a directory as a regular
# file with a trailing slash.
if obj.type == AREGTYPE and obj.name.endswith("/"):
obj.type = DIRTYPE
# The old GNU sparse format occupies some of the unused
# space in the buffer for up to 4 sparse structures.
# Save them for later processing in _proc_sparse().
if obj.type == GNUTYPE_SPARSE:
pos = 386
structs = []
for i in range(4):
try:
offset = nti(buf[pos:pos + 12])
numbytes = nti(buf[pos + 12:pos + 24])
except ValueError:
break
structs.append((offset, numbytes))
pos += 24
isextended = bool(buf[482])
origsize = nti(buf[483:495])
obj._sparse_structs = (structs, isextended, origsize)
# Remove redundant slashes from directories.
if obj.isdir():
obj.name = obj.name.rstrip("/")
# Reconstruct a ustar longname.
if prefix and obj.type not in GNU_TYPES:
obj.name = prefix + "/" + obj.name
return obj
@classmethod
def fromtarfile(cls, tarfile):
"""Return the next TarInfo object from TarFile object
tarfile.
"""
buf = tarfile.fileobj.read(BLOCKSIZE)
obj = cls.frombuf(buf, tarfile.encoding, tarfile.errors)
obj.offset = tarfile.fileobj.tell() - BLOCKSIZE
return obj._proc_member(tarfile)
#--------------------------------------------------------------------------
# The following are methods that are called depending on the type of a
# member. The entry point is _proc_member() which can be overridden in a
# subclass to add custom _proc_*() methods. A _proc_*() method MUST
# implement the following
# operations:
# 1. Set self.offset_data to the position where the data blocks begin,
# if there is data that follows.
# 2. Set tarfile.offset to the position where the next member's header will
# begin.
# 3. Return self or another valid TarInfo object.
def _proc_member(self, tarfile):
"""Choose the right processing method depending on
the type and call it.
"""
if self.type in (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK):
return self._proc_gnulong(tarfile)
elif self.type == GNUTYPE_SPARSE:
return self._proc_sparse(tarfile)
elif self.type in (XHDTYPE, XGLTYPE, SOLARIS_XHDTYPE):
return self._proc_pax(tarfile)
else:
return self._proc_builtin(tarfile)
def _proc_builtin(self, tarfile):
"""Process a builtin type or an unknown type which
will be treated as a regular file.
"""
self.offset_data = tarfile.fileobj.tell()
offset = self.offset_data
if self.isreg() or self.type not in SUPPORTED_TYPES:
# Skip the following data blocks.
offset += self._block(self.size)
tarfile.offset = offset
# Patch the TarInfo object with saved global
# header information.
self._apply_pax_info(tarfile.pax_headers, tarfile.encoding, tarfile.errors)
# Remove redundant slashes from directories. This is to be consistent
# with frombuf().
if self.isdir():
self.name = self.name.rstrip("/")
return self
def _proc_gnulong(self, tarfile):
"""Process the blocks that hold a GNU longname
or longlink member.
"""
buf = tarfile.fileobj.read(self._block(self.size))
# Fetch the next header and process it.
try:
next = self.fromtarfile(tarfile)
except HeaderError as e:
raise SubsequentHeaderError(str(e)) from None
# Patch the TarInfo object from the next header with
# the longname information.
next.offset = self.offset
if self.type == GNUTYPE_LONGNAME:
next.name = nts(buf, tarfile.encoding, tarfile.errors)
elif self.type == GNUTYPE_LONGLINK:
next.linkname = nts(buf, tarfile.encoding, tarfile.errors)
# Remove redundant slashes from directories. This is to be consistent
# with frombuf().
if next.isdir():
next.name = next.name.removesuffix("/")
return next
def _proc_sparse(self, tarfile):
"""Process a GNU sparse header plus extra headers.
"""
# We already collected some sparse structures in frombuf().
structs, isextended, origsize = self._sparse_structs
del self._sparse_structs
# Collect sparse structures from extended header blocks.
while isextended:
buf = tarfile.fileobj.read(BLOCKSIZE)
pos = 0
for i in range(21):
try:
offset = nti(buf[pos:pos + 12])
numbytes = nti(buf[pos + 12:pos + 24])
except ValueError:
break
if offset and numbytes:
structs.append((offset, numbytes))
pos += 24
isextended = bool(buf[504])
self.sparse = structs
self.offset_data = tarfile.fileobj.tell()
tarfile.offset = self.offset_data + self._block(self.size)
self.size = origsize
return self
def _proc_pax(self, tarfile):
"""Process an extended or global header as described in
POSIX.1-2008.
"""
# Read the header information.
buf = tarfile.fileobj.read(self._block(self.size))
# A pax header stores supplemental information for either
# the following file (extended) or all following files
# (global).
if self.type == XGLTYPE:
pax_headers = tarfile.pax_headers
else:
pax_headers = tarfile.pax_headers.copy()
# Parse pax header information. A record looks like that:
# "%d %s=%s\n" % (length, keyword, value). length is the size
# of the complete record including the length field itself and
# the newline.
pos = 0
encoding = None
raw_headers = []
while len(buf) > pos and buf[pos] != 0x00:
if not (match := _header_length_prefix_re.match(buf, pos)):
raise InvalidHeaderError("invalid header")
try:
length = int(match.group(1))
except ValueError:
raise InvalidHeaderError("invalid header")
# Headers must be at least 5 bytes, shortest being '5 x=\n'.
# Value is allowed to be empty.
if length < 5:
raise InvalidHeaderError("invalid header")
if pos + length > len(buf):
raise InvalidHeaderError("invalid header")
header_value_end_offset = match.start(1) + length - 1 # Last byte of the header
keyword_and_value = buf[match.end(1) + 1:header_value_end_offset]
raw_keyword, equals, raw_value = keyword_and_value.partition(b"=")
# Check the framing of the header. The last character must be '\n' (0x0A)
if not raw_keyword or equals != b"=" or buf[header_value_end_offset] != 0x0A:
raise InvalidHeaderError("invalid header")
raw_headers.append((length, raw_keyword, raw_value))
# Check if the pax header contains a hdrcharset field. This tells us
# the encoding of the path, linkpath, uname and gname fields. Normally,
# these fields are UTF-8 encoded but since POSIX.1-2008 tar
# implementations are allowed to store them as raw binary strings if
# the translation to UTF-8 fails. For the time being, we don't care about
# anything other than "BINARY". The only other value that is currently
# allowed by the standard is "ISO-IR 10646 2000 UTF-8" in other words UTF-8.
# Note that we only follow the initial 'hdrcharset' setting to preserve
# the initial behavior of the 'tarfile' module.
if raw_keyword == b"hdrcharset" and encoding is None:
if raw_value == b"BINARY":
encoding = tarfile.encoding
else: # This branch ensures only the first 'hdrcharset' header is used.
encoding = "utf-8"
pos += length
# If no explicit hdrcharset is set, we use UTF-8 as a default.
if encoding is None:
encoding = "utf-8"
# After parsing the raw headers we can decode them to text.
for length, raw_keyword, raw_value in raw_headers:
# Normally, we could just use "utf-8" as the encoding and "strict"
# as the error handler, but we better not take the risk. For
# example, GNU tar <= 1.23 is known to store filenames it cannot
# translate to UTF-8 as raw strings (unfortunately without a
# hdrcharset=BINARY header).
# We first try the strict standard encoding, and if that fails we
# fall back on the user's encoding and error handler.
keyword = self._decode_pax_field(raw_keyword, "utf-8", "utf-8",
tarfile.errors)
if keyword in PAX_NAME_FIELDS:
value = self._decode_pax_field(raw_value, encoding, tarfile.encoding,
tarfile.errors)
else:
value = self._decode_pax_field(raw_value, "utf-8", "utf-8",
tarfile.errors)
pax_headers[keyword] = value
# Fetch the next header.
try:
next = self.fromtarfile(tarfile)
except HeaderError as e:
raise SubsequentHeaderError(str(e)) from None
# Process GNU sparse information.
if "GNU.sparse.map" in pax_headers:
# GNU extended sparse format version 0.1.
self._proc_gnusparse_01(next, pax_headers)
elif "GNU.sparse.size" in pax_headers:
# GNU extended sparse format version 0.0.
self._proc_gnusparse_00(next, raw_headers)
elif pax_headers.get("GNU.sparse.major") == "1" and pax_headers.get("GNU.sparse.minor") == "0":
# GNU extended sparse format version 1.0.
self._proc_gnusparse_10(next, pax_headers, tarfile)
if self.type in (XHDTYPE, SOLARIS_XHDTYPE):
# Patch the TarInfo object with the extended header info.
next._apply_pax_info(pax_headers, tarfile.encoding, tarfile.errors)
next.offset = self.offset
if "size" in pax_headers:
# If the extended header replaces the size field,
# we need to recalculate the offset where the next
# header starts.
offset = next.offset_data
if next.isreg() or next.type not in SUPPORTED_TYPES:
offset += next._block(next.size)
tarfile.offset = offset
return next
def _proc_gnusparse_00(self, next, raw_headers):
"""Process a GNU tar extended sparse header, version 0.0.
"""
offsets = []
numbytes = []
for _, keyword, value in raw_headers:
if keyword == b"GNU.sparse.offset":
try:
offsets.append(int(value.decode()))
except ValueError:
raise InvalidHeaderError("invalid header")
elif keyword == b"GNU.sparse.numbytes":
try:
numbytes.append(int(value.decode()))
except ValueError:
raise InvalidHeaderError("invalid header")
next.sparse = list(zip(offsets, numbytes))
def _proc_gnusparse_01(self, next, pax_headers):
"""Process a GNU tar extended sparse header, version 0.1.
"""
sparse = [int(x) for x in pax_headers["GNU.sparse.map"].split(",")]
next.sparse = list(zip(sparse[::2], sparse[1::2]))
def _proc_gnusparse_10(self, next, pax_headers, tarfile):
"""Process a GNU tar extended sparse header, version 1.0.
"""
fields = None
sparse = []
buf = tarfile.fileobj.read(BLOCKSIZE)
fields, buf = buf.split(b"\n", 1)
fields = int(fields)
while len(sparse) < fields * 2:
if b"\n" not in buf:
buf += tarfile.fileobj.read(BLOCKSIZE)
number, buf = buf.split(b"\n", 1)
sparse.append(int(number))
next.offset_data = tarfile.fileobj.tell()
next.sparse = list(zip(sparse[::2], sparse[1::2]))
def _apply_pax_info(self, pax_headers, encoding, errors):
"""Replace fields with supplemental information from a previous
pax extended or global header.
"""
for keyword, value in pax_headers.items():
if keyword == "GNU.sparse.name":
setattr(self, "path", value)
elif keyword == "GNU.sparse.size":
setattr(self, "size", int(value))
elif keyword == "GNU.sparse.realsize":
setattr(self, "size", int(value))
elif keyword in PAX_FIELDS:
if keyword in PAX_NUMBER_FIELDS:
try:
value = PAX_NUMBER_FIELDS[keyword](value)
except ValueError:
value = 0
if keyword == "path":
value = value.rstrip("/")
setattr(self, keyword, value)
self.pax_headers = pax_headers.copy()
def _decode_pax_field(self, value, encoding, fallback_encoding, fallback_errors):
"""Decode a single field from a pax record.
"""
try:
return value.decode(encoding, "strict")
except UnicodeDecodeError:
return value.decode(fallback_encoding, fallback_errors)
def _block(self, count):
"""Round up a byte count by BLOCKSIZE and return it,
e.g. _block(834) => 1024.
"""
blocks, remainder = divmod(count, BLOCKSIZE)
if remainder:
blocks += 1
return blocks * BLOCKSIZE
def isreg(self):
'Return True if the Tarinfo object is a regular file.'
return self.type in REGULAR_TYPES
def isfile(self):
'Return True if the Tarinfo object is a regular file.'
return self.isreg()
def isdir(self):
'Return True if it is a directory.'
return self.type == DIRTYPE
def issym(self):
'Return True if it is a symbolic link.'
return self.type == SYMTYPE
def islnk(self):
'Return True if it is a hard link.'
return self.type == LNKTYPE
def ischr(self):
'Return True if it is a character device.'
return self.type == CHRTYPE
def isblk(self):
'Return True if it is a block device.'
return self.type == BLKTYPE
def isfifo(self):
'Return True if it is a FIFO.'
return self.type == FIFOTYPE
def issparse(self):
return self.sparse is not None
def isdev(self):
'Return True if it is one of character device, block device or FIFO.'
return self.type in (CHRTYPE, BLKTYPE, FIFOTYPE)
# class TarInfo
class TarFile(object):
"""The TarFile Class provides an interface to tar archives.
"""
debug = 0 # May be set from 0 (no msgs) to 3 (all msgs)
dereference = False # If true, add content of linked file to the
# tar file, else the link.
ignore_zeros = False # If true, skips empty or invalid blocks and
# continues processing.
errorlevel = 1 # If 0, fatal errors only appear in debug
# messages (if debug >= 0). If > 0, errors
# are passed to the caller as exceptions.
format = DEFAULT_FORMAT # The format to use when creating an archive.
encoding = ENCODING # Encoding for 8-bit character strings.
errors = None # Error handler for unicode conversion.
tarinfo = TarInfo # The default TarInfo class to use.
fileobject = ExFileObject # The file-object for extractfile().
extraction_filter = None # The default filter for extraction.
def __init__(self, name=None, mode="r", fileobj=None, format=None,
tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
errors="surrogateescape", pax_headers=None, debug=None,
errorlevel=None, copybufsize=None, stream=False):
"""Open an (uncompressed) tar archive 'name'. 'mode' is either 'r' to
read from an existing archive, 'a' to append data to an existing
file or 'w' to create a new file overwriting an existing one. 'mode'
defaults to 'r'.
If 'fileobj' is given, it is used for reading or writing data. If it
can be determined, 'mode' is overridden by 'fileobj's mode.
'fileobj' is not closed, when TarFile is closed.
"""
modes = {"r": "rb", "a": "r+b", "w": "wb", "x": "xb"}
if mode not in modes:
raise ValueError("mode must be 'r', 'a', 'w' or 'x'")
self.mode = mode
self._mode = modes[mode]
if not fileobj:
if self.mode == "a" and not os.path.exists(name):
# Create nonexistent files in append mode.
self.mode = "w"
self._mode = "wb"
fileobj = bltn_open(name, self._mode)
self._extfileobj = False
else:
if (name is None and hasattr(fileobj, "name") and
isinstance(fileobj.name, (str, bytes))):
name = fileobj.name
if hasattr(fileobj, "mode"):
self._mode = fileobj.mode
self._extfileobj = True
self.name = os.path.abspath(name) if name else None
self.fileobj = fileobj
self.stream = stream
# Init attributes.
if format is not None:
self.format = format
if tarinfo is not None:
self.tarinfo = tarinfo
if dereference is not None:
self.dereference = dereference
if ignore_zeros is not None:
self.ignore_zeros = ignore_zeros
if encoding is not None:
self.encoding = encoding
self.errors = errors
if pax_headers is not None and self.format == PAX_FORMAT:
self.pax_headers = pax_headers
else:
self.pax_headers = {}
if debug is not None:
self.debug = debug
if errorlevel is not None:
self.errorlevel = errorlevel
# Init datastructures.
self.copybufsize = copybufsize
self.closed = False
self.members = [] # list of members as TarInfo objects
self._loaded = False # flag if all members have been read
self.offset = self.fileobj.tell()
# current position in the archive file
self.inodes = {} # dictionary caching the inodes of
# archive members already added
self._unames = {} # Cached mappings of uid -> uname
self._gnames = {} # Cached mappings of gid -> gname
try:
if self.mode == "r":
self.firstmember = None
self.firstmember = self.next()
if self.mode == "a":
# Move to the end of the archive,
# before the first empty block.
while True:
self.fileobj.seek(self.offset)
try:
tarinfo = self.tarinfo.fromtarfile(self)
self.members.append(tarinfo)
except EOFHeaderError:
self.fileobj.seek(self.offset)
break
except HeaderError as e:
raise ReadError(str(e)) from None
if self.mode in ("a", "w", "x"):
self._loaded = True
if self.pax_headers:
buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
self.fileobj.write(buf)
self.offset += len(buf)
except:
if not self._extfileobj:
self.fileobj.close()
self.closed = True
raise
#--------------------------------------------------------------------------
# Below are the classmethods which act as alternate constructors to the
# TarFile class. The open() method is the only one that is needed for
# public use; it is the "super"-constructor and is able to select an
# adequate "sub"-constructor for a particular compression using the mapping
# from OPEN_METH.
#
# This concept allows one to subclass TarFile without losing the comfort of
# the super-constructor. A sub-constructor is registered and made available
# by adding it to the mapping in OPEN_METH.
@classmethod
def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
"""Open a tar archive for reading, writing or appending. Return
an appropriate TarFile class.
mode:
'r' or 'r:*' open for reading with transparent compression
'r:' open for reading exclusively uncompressed
'r:gz' open for reading with gzip compression
'r:bz2' open for reading with bzip2 compression
'r:xz' open for reading with lzma compression
'a' or 'a:' open for appending, creating the file if necessary
'w' or 'w:' open for writing without compression
'w:gz' open for writing with gzip compression
'w:bz2' open for writing with bzip2 compression
'w:xz' open for writing with lzma compression
'x' or 'x:' create a tarfile exclusively without compression, raise
an exception if the file is already created
'x:gz' create a gzip compressed tarfile, raise an exception
if the file is already created
'x:bz2' create a bzip2 compressed tarfile, raise an exception
if the file is already created
'x:xz' create an lzma compressed tarfile, raise an exception
if the file is already created
'r|*' open a stream of tar blocks with transparent compression
'r|' open an uncompressed stream of tar blocks for reading
'r|gz' open a gzip compressed stream of tar blocks
'r|bz2' open a bzip2 compressed stream of tar blocks
'r|xz' open an lzma compressed stream of tar blocks
'w|' open an uncompressed stream for writing
'w|gz' open a gzip compressed stream for writing
'w|bz2' open a bzip2 compressed stream for writing
'w|xz' open an lzma compressed stream for writing
"""
if not name and not fileobj:
raise ValueError("nothing to open")
if mode in ("r", "r:*"):
# Find out which *open() is appropriate for opening the file.
def not_compressed(comptype):
return cls.OPEN_METH[comptype] == 'taropen'
error_msgs = []
for comptype in sorted(cls.OPEN_METH, key=not_compressed):
func = getattr(cls, cls.OPEN_METH[comptype])
if fileobj is not None:
saved_pos = fileobj.tell()
try:
return func(name, "r", fileobj, **kwargs)
except (ReadError, CompressionError) as e:
error_msgs.append(f'- method {comptype}: {e!r}')
if fileobj is not None:
fileobj.seek(saved_pos)
continue
error_msgs_summary = '\n'.join(error_msgs)
raise ReadError(f"file could not be opened successfully:\n{error_msgs_summary}")
elif ":" in mode:
filemode, comptype = mode.split(":", 1)
filemode = filemode or "r"
comptype = comptype or "tar"
# Select the *open() function according to
# given compression.
if comptype in cls.OPEN_METH:
func = getattr(cls, cls.OPEN_METH[comptype])
else:
raise CompressionError("unknown compression type %r" % comptype)
return func(name, filemode, fileobj, **kwargs)
elif "|" in mode:
filemode, comptype = mode.split("|", 1)
filemode = filemode or "r"
comptype = comptype or "tar"
if filemode not in ("r", "w"):
raise ValueError("mode must be 'r' or 'w'")
compresslevel = kwargs.pop("compresslevel", 9)
stream = _Stream(name, filemode, comptype, fileobj, bufsize,
compresslevel)
try:
t = cls(name, filemode, stream, **kwargs)
except:
stream.close()
raise
t._extfileobj = False
return t
elif mode in ("a", "w", "x"):
return cls.taropen(name, mode, fileobj, **kwargs)
raise ValueError("undiscernible mode")
@classmethod
def taropen(cls, name, mode="r", fileobj=None, **kwargs):
"""Open uncompressed tar archive name for reading or writing.
"""
if mode not in ("r", "a", "w", "x"):
raise ValueError("mode must be 'r', 'a', 'w' or 'x'")
return cls(name, mode, fileobj, **kwargs)
@classmethod
def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
"""Open gzip compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if mode not in ("r", "w", "x"):
raise ValueError("mode must be 'r', 'w' or 'x'")
try:
from gzip import GzipFile
except ImportError:
raise CompressionError("gzip module is not available") from None
try:
fileobj = GzipFile(name, mode + "b", compresslevel, fileobj)
except OSError as e:
if fileobj is not None and mode == 'r':
raise ReadError("not a gzip file") from e
raise
try:
t = cls.taropen(name, mode, fileobj, **kwargs)
except OSError as e:
fileobj.close()
if mode == 'r':
raise ReadError("not a gzip file") from e
raise
except:
fileobj.close()
raise
t._extfileobj = False
return t
@classmethod
def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
"""Open bzip2 compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if mode not in ("r", "w", "x"):
raise ValueError("mode must be 'r', 'w' or 'x'")
try:
from bz2 import BZ2File
except ImportError:
raise CompressionError("bz2 module is not available") from None
fileobj = BZ2File(fileobj or name, mode, compresslevel=compresslevel)
try:
t = cls.taropen(name, mode, fileobj, **kwargs)
except (OSError, EOFError) as e:
fileobj.close()
if mode == 'r':
raise ReadError("not a bzip2 file") from e
raise
except:
fileobj.close()
raise
t._extfileobj = False
return t
@classmethod
def xzopen(cls, name, mode="r", fileobj=None, preset=None, **kwargs):
"""Open lzma compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if mode not in ("r", "w", "x"):
raise ValueError("mode must be 'r', 'w' or 'x'")
try:
from lzma import LZMAFile, LZMAError
except ImportError:
raise CompressionError("lzma module is not available") from None
fileobj = LZMAFile(fileobj or name, mode, preset=preset)
try:
t = cls.taropen(name, mode, fileobj, **kwargs)
except (LZMAError, EOFError) as e:
fileobj.close()
if mode == 'r':
raise ReadError("not an lzma file") from e
raise
except:
fileobj.close()
raise
t._extfileobj = False
return t
# All *open() methods are registered here.
OPEN_METH = {
"tar": "taropen", # uncompressed tar
"gz": "gzopen", # gzip compressed tar
"bz2": "bz2open", # bzip2 compressed tar
"xz": "xzopen" # lzma compressed tar
}
#--------------------------------------------------------------------------
# The public methods which TarFile provides:
def close(self):
"""Close the TarFile. In write-mode, two finishing zero blocks are
appended to the archive.
"""
if self.closed:
return
self.closed = True
try:
if self.mode in ("a", "w", "x"):
self.fileobj.write(NUL * (BLOCKSIZE * 2))
self.offset += (BLOCKSIZE * 2)
# fill up the end with zero-blocks
# (like option -b20 for tar does)
blocks, remainder = divmod(self.offset, RECORDSIZE)
if remainder > 0:
self.fileobj.write(NUL * (RECORDSIZE - remainder))
finally:
if not self._extfileobj:
self.fileobj.close()
def getmember(self, name):
"""Return a TarInfo object for member 'name'. If 'name' can not be
found in the archive, KeyError is raised. If a member occurs more
than once in the archive, its last occurrence is assumed to be the
most up-to-date version.
"""
tarinfo = self._getmember(name.rstrip('/'))
if tarinfo is None:
raise KeyError("filename %r not found" % name)
return tarinfo
def getmembers(self):
"""Return the members of the archive as a list of TarInfo objects. The
list has the same order as the members in the archive.
"""
self._check()
if not self._loaded: # if we want to obtain a list of
self._load() # all members, we first have to
# scan the whole archive.
return self.members
def getnames(self):
"""Return the members of the archive as a list of their names. It has
the same order as the list returned by getmembers().
"""
return [tarinfo.name for tarinfo in self.getmembers()]
def gettarinfo(self, name=None, arcname=None, fileobj=None):
"""Create a TarInfo object from the result of os.stat or equivalent
on an existing file. The file is either named by 'name', or
specified as a file object 'fileobj' with a file descriptor. If
given, 'arcname' specifies an alternative name for the file in the
archive, otherwise, the name is taken from the 'name' attribute of
'fileobj', or the 'name' argument. The name should be a text
string.
"""
self._check("awx")
# When fileobj is given, replace name by
# fileobj's real name.
if fileobj is not None:
name = fileobj.name
# Building the name of the member in the archive.
# Backward slashes are converted to forward slashes,
# Absolute paths are turned to relative paths.
if arcname is None:
arcname = name
drv, arcname = os.path.splitdrive(arcname)
arcname = arcname.replace(os.sep, "/")
arcname = arcname.lstrip("/")
# Now, fill the TarInfo object with
# information specific for the file.
tarinfo = self.tarinfo()
tarinfo._tarfile = self # To be removed in 3.16.
# Use os.stat or os.lstat, depending on if symlinks shall be resolved.
if fileobj is None:
if not self.dereference:
statres = os.lstat(name)
else:
statres = os.stat(name)
else:
statres = os.fstat(fileobj.fileno())
linkname = ""
stmd = statres.st_mode
if stat.S_ISREG(stmd):
inode = (statres.st_ino, statres.st_dev)
if not self.dereference and statres.st_nlink > 1 and \
inode in self.inodes and arcname != self.inodes[inode]:
# Is it a hardlink to an already
# archived file?
type = LNKTYPE
linkname = self.inodes[inode]
else:
# The inode is added only if its valid.
# For win32 it is always 0.
type = REGTYPE
if inode[0]:
self.inodes[inode] = arcname
elif stat.S_ISDIR(stmd):
type = DIRTYPE
elif stat.S_ISFIFO(stmd):
type = FIFOTYPE
elif stat.S_ISLNK(stmd):
type = SYMTYPE
linkname = os.readlink(name)
elif stat.S_ISCHR(stmd):
type = CHRTYPE
elif stat.S_ISBLK(stmd):
type = BLKTYPE
else:
return None
# Fill the TarInfo object with all
# information we can get.
tarinfo.name = arcname
tarinfo.mode = stmd
tarinfo.uid = statres.st_uid
tarinfo.gid = statres.st_gid
if type == REGTYPE:
tarinfo.size = statres.st_size
else:
tarinfo.size = 0
tarinfo.mtime = statres.st_mtime
tarinfo.type = type
tarinfo.linkname = linkname
# Calls to pwd.getpwuid() and grp.getgrgid() tend to be expensive. To
# speed things up, cache the resolved usernames and group names.
if pwd:
if tarinfo.uid not in self._unames:
try:
self._unames[tarinfo.uid] = pwd.getpwuid(tarinfo.uid)[0]
except KeyError:
self._unames[tarinfo.uid] = ''
tarinfo.uname = self._unames[tarinfo.uid]
if grp:
if tarinfo.gid not in self._gnames:
try:
self._gnames[tarinfo.gid] = grp.getgrgid(tarinfo.gid)[0]
except KeyError:
self._gnames[tarinfo.gid] = ''
tarinfo.gname = self._gnames[tarinfo.gid]
if type in (CHRTYPE, BLKTYPE):
if hasattr(os, "major") and hasattr(os, "minor"):
tarinfo.devmajor = os.major(statres.st_rdev)
tarinfo.devminor = os.minor(statres.st_rdev)
return tarinfo
def list(self, verbose=True, *, members=None):
"""Print a table of contents to sys.stdout. If 'verbose' is False, only
the names of the members are printed. If it is True, an 'ls -l'-like
output is produced. 'members' is optional and must be a subset of the
list returned by getmembers().
"""
# Convert tarinfo type to stat type.
type2mode = {REGTYPE: stat.S_IFREG, SYMTYPE: stat.S_IFLNK,
FIFOTYPE: stat.S_IFIFO, CHRTYPE: stat.S_IFCHR,
DIRTYPE: stat.S_IFDIR, BLKTYPE: stat.S_IFBLK}
self._check()
if members is None:
members = self
for tarinfo in members:
if verbose:
if tarinfo.mode is None:
_safe_print("??????????")
else:
modetype = type2mode.get(tarinfo.type, 0)
_safe_print(stat.filemode(modetype | tarinfo.mode))
_safe_print("%s/%s" % (tarinfo.uname or tarinfo.uid,
tarinfo.gname or tarinfo.gid))
if tarinfo.ischr() or tarinfo.isblk():
_safe_print("%10s" %
("%d,%d" % (tarinfo.devmajor, tarinfo.devminor)))
else:
_safe_print("%10d" % tarinfo.size)
if tarinfo.mtime is None:
_safe_print("????-??-?? ??:??:??")
else:
_safe_print("%d-%02d-%02d %02d:%02d:%02d" \
% time.localtime(tarinfo.mtime)[:6])
_safe_print(tarinfo.name + ("/" if tarinfo.isdir() else ""))
if verbose:
if tarinfo.issym():
_safe_print("-> " + tarinfo.linkname)
if tarinfo.islnk():
_safe_print("link to " + tarinfo.linkname)
print()
def add(self, name, arcname=None, recursive=True, *, filter=None):
"""Add the file 'name' to the archive. 'name' may be any type of file
(directory, fifo, symbolic link, etc.). If given, 'arcname'
specifies an alternative name for the file in the archive.
Directories are added recursively by default. This can be avoided by
setting 'recursive' to False. 'filter' is a function
that expects a TarInfo object argument and returns the changed
TarInfo object, if it returns None the TarInfo object will be
excluded from the archive.
"""
self._check("awx")
if arcname is None:
arcname = name
# Skip if somebody tries to archive the archive...
if self.name is not None and os.path.abspath(name) == self.name:
self._dbg(2, "tarfile: Skipped %r" % name)
return
self._dbg(1, name)
# Create a TarInfo object from the file.
tarinfo = self.gettarinfo(name, arcname)
if tarinfo is None:
self._dbg(1, "tarfile: Unsupported type %r" % name)
return
# Change or exclude the TarInfo object.
if filter is not None:
tarinfo = filter(tarinfo)
if tarinfo is None:
self._dbg(2, "tarfile: Excluded %r" % name)
return
# Append the tar header and data to the archive.
if tarinfo.isreg():
with bltn_open(name, "rb") as f:
self.addfile(tarinfo, f)
elif tarinfo.isdir():
self.addfile(tarinfo)
if recursive:
for f in sorted(os.listdir(name)):
self.add(os.path.join(name, f), os.path.join(arcname, f),
recursive, filter=filter)
else:
self.addfile(tarinfo)
def addfile(self, tarinfo, fileobj=None):
"""Add the TarInfo object 'tarinfo' to the archive. If 'tarinfo' represents
a non zero-size regular file, the 'fileobj' argument should be a binary file,
and tarinfo.size bytes are read from it and added to the archive.
You can create TarInfo objects directly, or by using gettarinfo().
"""
self._check("awx")
if fileobj is None and tarinfo.isreg() and tarinfo.size != 0:
raise ValueError("fileobj not provided for non zero-size regular file")
tarinfo = copy.copy(tarinfo)
buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
self.fileobj.write(buf)
self.offset += len(buf)
bufsize=self.copybufsize
# If there's data to follow, append it.
if fileobj is not None:
copyfileobj(fileobj, self.fileobj, tarinfo.size, bufsize=bufsize)
blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
if remainder > 0:
self.fileobj.write(NUL * (BLOCKSIZE - remainder))
blocks += 1
self.offset += blocks * BLOCKSIZE
self.members.append(tarinfo)
def _get_filter_function(self, filter):
if filter is None:
filter = self.extraction_filter
if filter is None:
return data_filter
if isinstance(filter, str):
raise TypeError(
'String names are not supported for '
+ 'TarFile.extraction_filter. Use a function such as '
+ 'tarfile.data_filter directly.')
return filter
if callable(filter):
return filter
try:
return _NAMED_FILTERS[filter]
except KeyError:
raise ValueError(f"filter {filter!r} not found") from None
def extractall(self, path=".", members=None, *, numeric_owner=False,
filter=None):
"""Extract all members from the archive to the current working
directory and set owner, modification time and permissions on
directories afterwards. 'path' specifies a different directory
to extract to. 'members' is optional and must be a subset of the
list returned by getmembers(). If 'numeric_owner' is True, only
the numbers for user/group names are used and not the names.
The 'filter' function will be called on each member just
before extraction.
It can return a changed TarInfo or None to skip the member.
String names of common filters are accepted.
"""
directories = []
filter_function = self._get_filter_function(filter)
if members is None:
members = self
for member in members:
tarinfo = self._get_extract_tarinfo(member, filter_function, path)
if tarinfo is None:
continue
if tarinfo.isdir():
# For directories, delay setting attributes until later,
# since permissions can interfere with extraction and
# extracting contents can reset mtime.
directories.append(tarinfo)
self._extract_one(tarinfo, path, set_attrs=not tarinfo.isdir(),
numeric_owner=numeric_owner)
# Reverse sort directories.
directories.sort(key=lambda a: a.name, reverse=True)
# Set correct owner, mtime and filemode on directories.
for tarinfo in directories:
dirpath = os.path.join(path, tarinfo.name)
try:
self.chown(tarinfo, dirpath, numeric_owner=numeric_owner)
self.utime(tarinfo, dirpath)
self.chmod(tarinfo, dirpath)
except ExtractError as e:
self._handle_nonfatal_error(e)
def extract(self, member, path="", set_attrs=True, *, numeric_owner=False,
filter=None):
"""Extract a member from the archive to the current working directory,
using its full name. Its file information is extracted as accurately
as possible. 'member' may be a filename or a TarInfo object. You can
specify a different directory using 'path'. File attributes (owner,
mtime, mode) are set unless 'set_attrs' is False. If 'numeric_owner'
is True, only the numbers for user/group names are used and not
the names.
The 'filter' function will be called before extraction.
It can return a changed TarInfo or None to skip the member.
String names of common filters are accepted.
"""
filter_function = self._get_filter_function(filter)
tarinfo = self._get_extract_tarinfo(member, filter_function, path)
if tarinfo is not None:
self._extract_one(tarinfo, path, set_attrs, numeric_owner)
def _get_extract_tarinfo(self, member, filter_function, path):
"""Get filtered TarInfo (or None) from member, which might be a str"""
if isinstance(member, str):
tarinfo = self.getmember(member)
else:
tarinfo = member
unfiltered = tarinfo
try:
tarinfo = filter_function(tarinfo, path)
except (OSError, FilterError) as e:
self._handle_fatal_error(e)
except ExtractError as e:
self._handle_nonfatal_error(e)
if tarinfo is None:
self._dbg(2, "tarfile: Excluded %r" % unfiltered.name)
return None
# Prepare the link target for makelink().
if tarinfo.islnk():
tarinfo = copy.copy(tarinfo)
tarinfo._link_target = os.path.join(path, tarinfo.linkname)
return tarinfo
def _extract_one(self, tarinfo, path, set_attrs, numeric_owner):
"""Extract from filtered tarinfo to disk"""
self._check("r")
try:
self._extract_member(tarinfo, os.path.join(path, tarinfo.name),
set_attrs=set_attrs,
numeric_owner=numeric_owner)
except OSError as e:
self._handle_fatal_error(e)
except ExtractError as e:
self._handle_nonfatal_error(e)
def _handle_nonfatal_error(self, e):
"""Handle non-fatal error (ExtractError) according to errorlevel"""
if self.errorlevel > 1:
raise
else:
self._dbg(1, "tarfile: %s" % e)
def _handle_fatal_error(self, e):
"""Handle "fatal" error according to self.errorlevel"""
if self.errorlevel > 0:
raise
elif isinstance(e, OSError):
if e.filename is None:
self._dbg(1, "tarfile: %s" % e.strerror)
else:
self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
else:
self._dbg(1, "tarfile: %s %s" % (type(e).__name__, e))
def extractfile(self, member):
"""Extract a member from the archive as a file object. 'member' may be
a filename or a TarInfo object. If 'member' is a regular file or
a link, an io.BufferedReader object is returned. For all other
existing members, None is returned. If 'member' does not appear
in the archive, KeyError is raised.
"""
self._check("r")
if isinstance(member, str):
tarinfo = self.getmember(member)
else:
tarinfo = member
if tarinfo.isreg() or tarinfo.type not in SUPPORTED_TYPES:
# Members with unknown types are treated as regular files.
return self.fileobject(self, tarinfo)
elif tarinfo.islnk() or tarinfo.issym():
if isinstance(self.fileobj, _Stream):
# A small but ugly workaround for the case that someone tries
# to extract a (sym)link as a file-object from a non-seekable
# stream of tar blocks.
raise StreamError("cannot extract (sym)link as file object")
else:
# A (sym)link's file object is its target's file object.
return self.extractfile(self._find_link_target(tarinfo))
else:
# If there's no data associated with the member (directory, chrdev,
# blkdev, etc.), return None instead of a file object.
return None
def _extract_member(self, tarinfo, targetpath, set_attrs=True,
numeric_owner=False):
"""Extract the TarInfo object tarinfo to a physical
file called targetpath.
"""
# Fetch the TarInfo object for the given name
# and build the destination pathname, replacing
# forward slashes to platform specific separators.
targetpath = targetpath.rstrip("/")
targetpath = targetpath.replace("/", os.sep)
# Create all upper directories.
upperdirs = os.path.dirname(targetpath)
if upperdirs and not os.path.exists(upperdirs):
# Create directories that are not part of the archive with
# default permissions.
os.makedirs(upperdirs, exist_ok=True)
if tarinfo.islnk() or tarinfo.issym():
self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
else:
self._dbg(1, tarinfo.name)
if tarinfo.isreg():
self.makefile(tarinfo, targetpath)
elif tarinfo.isdir():
self.makedir(tarinfo, targetpath)
elif tarinfo.isfifo():
self.makefifo(tarinfo, targetpath)
elif tarinfo.ischr() or tarinfo.isblk():
self.makedev(tarinfo, targetpath)
elif tarinfo.islnk() or tarinfo.issym():
self.makelink(tarinfo, targetpath)
elif tarinfo.type not in SUPPORTED_TYPES:
self.makeunknown(tarinfo, targetpath)
else:
self.makefile(tarinfo, targetpath)
if set_attrs:
self.chown(tarinfo, targetpath, numeric_owner)
if not tarinfo.issym():
self.chmod(tarinfo, targetpath)
self.utime(tarinfo, targetpath)
#--------------------------------------------------------------------------
# Below are the different file methods. They are called via
# _extract_member() when extract() is called. They can be replaced in a
# subclass to implement other functionality.
def makedir(self, tarinfo, targetpath):
"""Make a directory called targetpath.
"""
try:
if tarinfo.mode is None:
# Use the system's default mode
os.mkdir(targetpath)
else:
# Use a safe mode for the directory, the real mode is set
# later in _extract_member().
os.mkdir(targetpath, 0o700)
except FileExistsError:
if not os.path.isdir(targetpath):
raise
def makefile(self, tarinfo, targetpath):
"""Make a file called targetpath.
"""
source = self.fileobj
source.seek(tarinfo.offset_data)
bufsize = self.copybufsize
with bltn_open(targetpath, "wb") as target:
if tarinfo.sparse is not None:
for offset, size in tarinfo.sparse:
target.seek(offset)
copyfileobj(source, target, size, ReadError, bufsize)
target.seek(tarinfo.size)
target.truncate()
else:
copyfileobj(source, target, tarinfo.size, ReadError, bufsize)
def makeunknown(self, tarinfo, targetpath):
"""Make a file from a TarInfo object with an unknown type
at targetpath.
"""
self.makefile(tarinfo, targetpath)
self._dbg(1, "tarfile: Unknown file type %r, " \
"extracted as regular file." % tarinfo.type)
def makefifo(self, tarinfo, targetpath):
"""Make a fifo called targetpath.
"""
if hasattr(os, "mkfifo"):
os.mkfifo(targetpath)
else:
raise ExtractError("fifo not supported by system")
def makedev(self, tarinfo, targetpath):
"""Make a character or block device called targetpath.
"""
if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
raise ExtractError("special devices not supported by system")
mode = tarinfo.mode
if mode is None:
# Use mknod's default
mode = 0o600
if tarinfo.isblk():
mode |= stat.S_IFBLK
else:
mode |= stat.S_IFCHR
os.mknod(targetpath, mode,
os.makedev(tarinfo.devmajor, tarinfo.devminor))
def makelink(self, tarinfo, targetpath):
"""Make a (symbolic) link called targetpath. If it cannot be created
(platform limitation), we try to make a copy of the referenced file
instead of a link.
"""
try:
# For systems that support symbolic and hard links.
if tarinfo.issym():
if os.path.lexists(targetpath):
# Avoid FileExistsError on following os.symlink.
os.unlink(targetpath)
os.symlink(tarinfo.linkname, targetpath)
else:
if os.path.exists(tarinfo._link_target):
os.link(tarinfo._link_target, targetpath)
else:
self._extract_member(self._find_link_target(tarinfo),
targetpath)
except symlink_exception:
try:
self._extract_member(self._find_link_target(tarinfo),
targetpath)
except KeyError:
raise ExtractError("unable to resolve link inside archive") from None
def chown(self, tarinfo, targetpath, numeric_owner):
"""Set owner of targetpath according to tarinfo. If numeric_owner
is True, use .gid/.uid instead of .gname/.uname. If numeric_owner
is False, fall back to .gid/.uid when the search based on name
fails.
"""
if hasattr(os, "geteuid") and os.geteuid() == 0:
# We have to be root to do so.
g = tarinfo.gid
u = tarinfo.uid
if not numeric_owner:
try:
if grp and tarinfo.gname:
g = grp.getgrnam(tarinfo.gname)[2]
except KeyError:
pass
try:
if pwd and tarinfo.uname:
u = pwd.getpwnam(tarinfo.uname)[2]
except KeyError:
pass
if g is None:
g = -1
if u is None:
u = -1
try:
if tarinfo.issym() and hasattr(os, "lchown"):
os.lchown(targetpath, u, g)
else:
os.chown(targetpath, u, g)
except (OSError, OverflowError) as e:
# OverflowError can be raised if an ID doesn't fit in 'id_t'
raise ExtractError("could not change owner") from e
def chmod(self, tarinfo, targetpath):
"""Set file permissions of targetpath according to tarinfo.
"""
if tarinfo.mode is None:
return
try:
os.chmod(targetpath, tarinfo.mode)
except OSError as e:
raise ExtractError("could not change mode") from e
def utime(self, tarinfo, targetpath):
"""Set modification time of targetpath according to tarinfo.
"""
mtime = tarinfo.mtime
if mtime is None:
return
if not hasattr(os, 'utime'):
return
try:
os.utime(targetpath, (mtime, mtime))
except OSError as e:
raise ExtractError("could not change modification time") from e
#--------------------------------------------------------------------------
def next(self):
"""Return the next member of the archive as a TarInfo object, when
TarFile is opened for reading. Return None if there is no more
available.
"""
self._check("ra")
if self.firstmember is not None:
m = self.firstmember
self.firstmember = None
return m
# Advance the file pointer.
if self.offset != self.fileobj.tell():
if self.offset == 0:
return None
self.fileobj.seek(self.offset - 1)
if not self.fileobj.read(1):
raise ReadError("unexpected end of data")
# Read the next block.
tarinfo = None
while True:
try:
tarinfo = self.tarinfo.fromtarfile(self)
except EOFHeaderError as e:
if self.ignore_zeros:
self._dbg(2, "0x%X: %s" % (self.offset, e))
self.offset += BLOCKSIZE
continue
except InvalidHeaderError as e:
if self.ignore_zeros:
self._dbg(2, "0x%X: %s" % (self.offset, e))
self.offset += BLOCKSIZE
continue
elif self.offset == 0:
raise ReadError(str(e)) from None
except EmptyHeaderError:
if self.offset == 0:
raise ReadError("empty file") from None
except TruncatedHeaderError as e:
if self.offset == 0:
raise ReadError(str(e)) from None
except SubsequentHeaderError as e:
raise ReadError(str(e)) from None
except Exception as e:
try:
import zlib
if isinstance(e, zlib.error):
raise ReadError(f'zlib error: {e}') from None
else:
raise e
except ImportError:
raise e
break
if tarinfo is not None:
# if streaming the file we do not want to cache the tarinfo
if not self.stream:
self.members.append(tarinfo)
else:
self._loaded = True
return tarinfo
#--------------------------------------------------------------------------
# Little helper methods:
def _getmember(self, name, tarinfo=None, normalize=False):
"""Find an archive member by name from bottom to top.
If tarinfo is given, it is used as the starting point.
"""
# Ensure that all members have been loaded.
members = self.getmembers()
# Limit the member search list up to tarinfo.
skipping = False
if tarinfo is not None:
try:
index = members.index(tarinfo)
except ValueError:
# The given starting point might be a (modified) copy.
# We'll later skip members until we find an equivalent.
skipping = True
else:
# Happy fast path
members = members[:index]
if normalize:
name = os.path.normpath(name)
for member in reversed(members):
if skipping:
if tarinfo.offset == member.offset:
skipping = False
continue
if normalize:
member_name = os.path.normpath(member.name)
else:
member_name = member.name
if name == member_name:
return member
if skipping:
# Starting point was not found
raise ValueError(tarinfo)
def _load(self):
"""Read through the entire archive file and look for readable
members. This should not run if the file is set to stream.
"""
if not self.stream:
while self.next() is not None:
pass
self._loaded = True
def _check(self, mode=None):
"""Check if TarFile is still open, and if the operation's mode
corresponds to TarFile's mode.
"""
if self.closed:
raise OSError("%s is closed" % self.__class__.__name__)
if mode is not None and self.mode not in mode:
raise OSError("bad operation for mode %r" % self.mode)
def _find_link_target(self, tarinfo):
"""Find the target member of a symlink or hardlink member in the
archive.
"""
if tarinfo.issym():
# Always search the entire archive.
linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
limit = None
else:
# Search the archive before the link, because a hard link is
# just a reference to an already archived file.
linkname = tarinfo.linkname
limit = tarinfo
member = self._getmember(linkname, tarinfo=limit, normalize=True)
if member is None:
raise KeyError("linkname %r not found" % linkname)
return member
def __iter__(self):
"""Provide an iterator object.
"""
if self._loaded:
yield from self.members
return
# Yield items using TarFile's next() method.
# When all members have been read, set TarFile as _loaded.
index = 0
# Fix for SF #1100429: Under rare circumstances it can
# happen that getmembers() is called during iteration,
# which will have already exhausted the next() method.
if self.firstmember is not None:
tarinfo = self.next()
index += 1
yield tarinfo
while True:
if index < len(self.members):
tarinfo = self.members[index]
elif not self._loaded:
tarinfo = self.next()
if not tarinfo:
self._loaded = True
return
else:
return
index += 1
yield tarinfo
def _dbg(self, level, msg):
"""Write debugging output to sys.stderr.
"""
if level <= self.debug:
print(msg, file=sys.stderr)
def __enter__(self):
self._check()
return self
def __exit__(self, type, value, traceback):
if type is None:
self.close()
else:
# An exception occurred. We must not call close() because
# it would try to write end-of-archive blocks and padding.
if not self._extfileobj:
self.fileobj.close()
self.closed = True
#--------------------
# exported functions
#--------------------
def is_tarfile(name):
"""Return True if name points to a tar archive that we
are able to handle, else return False.
'name' should be a string, file, or file-like object.
"""
try:
if hasattr(name, "read"):
pos = name.tell()
t = open(fileobj=name)
name.seek(pos)
else:
t = open(name)
t.close()
return True
except TarError:
return False
open = TarFile.open
def main():
import argparse
description = 'A simple command-line interface for tarfile module.'
parser = argparse.ArgumentParser(description=description)
parser.add_argument('-v', '--verbose', action='store_true', default=False,
help='Verbose output')
parser.add_argument('--filter', metavar='<filtername>',
choices=_NAMED_FILTERS,
help='Filter for extraction')
group = parser.add_mutually_exclusive_group(required=True)
group.add_argument('-l', '--list', metavar='<tarfile>',
help='Show listing of a tarfile')
group.add_argument('-e', '--extract', nargs='+',
metavar=('<tarfile>', '<output_dir>'),
help='Extract tarfile into target dir')
group.add_argument('-c', '--create', nargs='+',
metavar=('<name>', '<file>'),
help='Create tarfile from sources')
group.add_argument('-t', '--test', metavar='<tarfile>',
help='Test if a tarfile is valid')
args = parser.parse_args()
if args.filter and args.extract is None:
parser.exit(1, '--filter is only valid for extraction\n')
if args.test is not None:
src = args.test
if is_tarfile(src):
with open(src, 'r') as tar:
tar.getmembers()
print(tar.getmembers(), file=sys.stderr)
if args.verbose:
print('{!r} is a tar archive.'.format(src))
else:
parser.exit(1, '{!r} is not a tar archive.\n'.format(src))
elif args.list is not None:
src = args.list
if is_tarfile(src):
with TarFile.open(src, 'r:*') as tf:
tf.list(verbose=args.verbose)
else:
parser.exit(1, '{!r} is not a tar archive.\n'.format(src))
elif args.extract is not None:
if len(args.extract) == 1:
src = args.extract[0]
curdir = os.curdir
elif len(args.extract) == 2:
src, curdir = args.extract
else:
parser.exit(1, parser.format_help())
if is_tarfile(src):
with TarFile.open(src, 'r:*') as tf:
tf.extractall(path=curdir, filter=args.filter)
if args.verbose:
if curdir == '.':
msg = '{!r} file is extracted.'.format(src)
else:
msg = ('{!r} file is extracted '
'into {!r} directory.').format(src, curdir)
print(msg)
else:
parser.exit(1, '{!r} is not a tar archive.\n'.format(src))
elif args.create is not None:
tar_name = args.create.pop(0)
_, ext = os.path.splitext(tar_name)
compressions = {
# gz
'.gz': 'gz',
'.tgz': 'gz',
# xz
'.xz': 'xz',
'.txz': 'xz',
# bz2
'.bz2': 'bz2',
'.tbz': 'bz2',
'.tbz2': 'bz2',
'.tb2': 'bz2',
}
tar_mode = 'w:' + compressions[ext] if ext in compressions else 'w'
tar_files = args.create
with TarFile.open(tar_name, tar_mode) as tf:
for file_name in tar_files:
tf.add(file_name)
if args.verbose:
print('{!r} file created.'.format(tar_name))
if __name__ == '__main__':
main()
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