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cpython/Lib/tarfile.py
Neal Norwitz f339654280 Patch #1338314, Bug #1336623: fix tarfile so it can extract 
REGTYPE directories from tarfiles written by old programs.

Will backport.
2005-10-28 05:52:22 +00:00

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#!/usr/bin/env python
# -*- coding: iso-8859-1 -*-
#-------------------------------------------------------------------
# tarfile.py
#-------------------------------------------------------------------
# Copyright (C) 2002 Lars Gustäbel <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__ = "$Revision$"
# $Source$
version = "0.6.4"
__author__ = "Lars Gustäbel (lars@gustaebel.de)"
__date__ = "$Date$"
__cvsid__ = "$Id$"
__credits__ = "Gustavo Niemeyer, Niels Gustäbel, Richard Townsend."
#---------
# Imports
#---------
import sys
import os
import shutil
import stat
import errno
import time
import struct
if sys.platform == 'mac':
# This module needs work for MacOS9, especially in the area of pathname
# handling. In many places it is assumed a simple substitution of / by the
# local os.path.sep is good enough to convert pathnames, but this does not
# work with the mac rooted:path:name versus :nonrooted:path:name syntax
raise ImportError, "tarfile does not work for platform==mac"
try:
import grp, pwd
except ImportError:
grp = pwd = None
# from tarfile import *
__all__ = ["TarFile", "TarInfo", "is_tarfile", "TarError"]
#---------------------------------------------------------
# tar constants
#---------------------------------------------------------
NUL = "\0" # the null character
BLOCKSIZE = 512 # length of processing blocks
RECORDSIZE = BLOCKSIZE * 20 # length of records
MAGIC = "ustar" # magic tar string
VERSION = "00" # version number
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
MAXSIZE_MEMBER = 077777777777L # maximum size of a file (11 octal digits)
REGTYPE = "0" # regular file
AREGTYPE = "\0" # regular file
LNKTYPE = "1" # link (inside tarfile)
SYMTYPE = "2" # symbolic link
CHRTYPE = "3" # character special device
BLKTYPE = "4" # block special device
DIRTYPE = "5" # directory
FIFOTYPE = "6" # fifo special device
CONTTYPE = "7" # contiguous file
GNUTYPE_LONGNAME = "L" # GNU tar extension for longnames
GNUTYPE_LONGLINK = "K" # GNU tar extension for longlink
GNUTYPE_SPARSE = "S" # GNU tar extension for sparse file
#---------------------------------------------------------
# tarfile constants
#---------------------------------------------------------
SUPPORTED_TYPES = (REGTYPE, AREGTYPE, LNKTYPE, # file types that tarfile
SYMTYPE, DIRTYPE, FIFOTYPE, # can cope with.
CONTTYPE, CHRTYPE, BLKTYPE,
GNUTYPE_LONGNAME, GNUTYPE_LONGLINK,
GNUTYPE_SPARSE)
REGULAR_TYPES = (REGTYPE, AREGTYPE, # file types that somehow
CONTTYPE, GNUTYPE_SPARSE) # represent regular files
#---------------------------------------------------------
# Bits used in the mode field, values in octal.
#---------------------------------------------------------
S_IFLNK = 0120000 # symbolic link
S_IFREG = 0100000 # regular file
S_IFBLK = 0060000 # block device
S_IFDIR = 0040000 # directory
S_IFCHR = 0020000 # character device
S_IFIFO = 0010000 # fifo
TSUID = 04000 # set UID on execution
TSGID = 02000 # set GID on execution
TSVTX = 01000 # reserved
TUREAD = 0400 # read by owner
TUWRITE = 0200 # write by owner
TUEXEC = 0100 # execute/search by owner
TGREAD = 0040 # read by group
TGWRITE = 0020 # write by group
TGEXEC = 0010 # execute/search by group
TOREAD = 0004 # read by other
TOWRITE = 0002 # write by other
TOEXEC = 0001 # execute/search by other
#---------------------------------------------------------
# Some useful functions
#---------------------------------------------------------
def nts(s):
"""Convert a null-terminated string buffer to a python string.
"""
return s.rstrip(NUL)
def calc_chksum(buf):
"""Calculate the checksum for a member's header. It's a simple addition
of all bytes, treating the chksum field as if filled with spaces.
buf is a 512 byte long string buffer which holds the header.
"""
chk = 256 # chksum field is treated as blanks,
# so the initial value is 8 * ord(" ")
for c in buf[:148]: chk += ord(c) # sum up all bytes before chksum
for c in buf[156:]: chk += ord(c) # sum up all bytes after chksum
return chk
def copyfileobj(src, dst, length=None):
"""Copy length bytes from fileobj src to fileobj dst.
If length is None, copy the entire content.
"""
if length == 0:
return
if length is None:
shutil.copyfileobj(src, dst)
return
BUFSIZE = 16 * 1024
blocks, remainder = divmod(length, BUFSIZE)
for b in xrange(blocks):
buf = src.read(BUFSIZE)
if len(buf) < BUFSIZE:
raise IOError, "end of file reached"
dst.write(buf)
if remainder != 0:
buf = src.read(remainder)
if len(buf) < remainder:
raise IOError, "end of file reached"
dst.write(buf)
return
filemode_table = (
((S_IFLNK, "l"),
(S_IFREG, "-"),
(S_IFBLK, "b"),
(S_IFDIR, "d"),
(S_IFCHR, "c"),
(S_IFIFO, "p")),
((TUREAD, "r"),),
((TUWRITE, "w"),),
((TUEXEC|TSUID, "s"),
(TSUID, "S"),
(TUEXEC, "x")),
((TGREAD, "r"),),
((TGWRITE, "w"),),
((TGEXEC|TSGID, "s"),
(TSGID, "S"),
(TGEXEC, "x")),
((TOREAD, "r"),),
((TOWRITE, "w"),),
((TOEXEC|TSVTX, "t"),
(TSVTX, "T"),
(TOEXEC, "x"))
)
def filemode(mode):
"""Convert a file's mode to a string of the form
-rwxrwxrwx.
Used by TarFile.list()
"""
perm = []
for table in filemode_table:
for bit, char in table:
if mode & bit == bit:
perm.append(char)
break
else:
perm.append("-")
return "".join(perm)
if os.sep != "/":
normpath = lambda path: os.path.normpath(path).replace(os.sep, "/")
else:
normpath = os.path.normpath
class TarError(Exception):
"""Base exception."""
pass
class ExtractError(TarError):
"""General exception for extract errors."""
pass
class ReadError(TarError):
"""Exception for unreadble tar archives."""
pass
class CompressionError(TarError):
"""Exception for unavailable compression methods."""
pass
class StreamError(TarError):
"""Exception for unsupported operations on stream-like TarFiles."""
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)
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 and is accessed
blockwise. Use of gzip or bzip2 compression is possible.
A stream-like object could be for example: sys.stdin,
sys.stdout, a socket, a tape device etc.
_Stream is intended to be used only internally.
"""
def __init__(self, name, mode, comptype, fileobj, bufsize):
"""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 = ""
self.pos = 0L
self.closed = False
if comptype == "gz":
try:
import zlib
except ImportError:
raise CompressionError, "zlib module is not available"
self.zlib = zlib
self.crc = zlib.crc32("")
if mode == "r":
self._init_read_gz()
else:
self._init_write_gz()
if comptype == "bz2":
try:
import bz2
except ImportError:
raise CompressionError, "bz2 module is not available"
if mode == "r":
self.dbuf = ""
self.cmp = bz2.BZ2Decompressor()
else:
self.cmp = bz2.BZ2Compressor()
def __del__(self):
if hasattr(self, "closed") and not self.closed:
self.close()
def _init_write_gz(self):
"""Initialize for writing with gzip compression.
"""
self.cmp = self.zlib.compressobj(9, self.zlib.DEFLATED,
-self.zlib.MAX_WBITS,
self.zlib.DEF_MEM_LEVEL,
0)
timestamp = struct.pack("<L", long(time.time()))
self.__write("\037\213\010\010%s\002\377" % timestamp)
if self.name.endswith(".gz"):
self.name = self.name[:-3]
self.__write(self.name + 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
if self.mode == "w" and self.comptype != "tar":
self.buf += self.cmp.flush()
if self.mode == "w" and self.buf:
blocks, remainder = divmod(len(self.buf), self.bufsize)
if remainder > 0:
self.buf += NUL * (self.bufsize - remainder)
self.fileobj.write(self.buf)
self.buf = ""
if self.comptype == "gz":
self.fileobj.write(struct.pack("<l", self.crc))
self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFFL))
if not self._extfileobj:
self.fileobj.close()
self.closed = True
def _init_read_gz(self):
"""Initialize for reading a gzip compressed fileobj.
"""
self.cmp = self.zlib.decompressobj(-self.zlib.MAX_WBITS)
self.dbuf = ""
# taken from gzip.GzipFile with some alterations
if self.__read(2) != "\037\213":
raise ReadError, "not a gzip file"
if self.__read(1) != "\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 xrange(blocks):
self.read(self.bufsize)
self.read(remainder)
else:
raise StreamError, "seeking backwards is not allowed"
return self.pos
def read(self, size=None):
"""Return the next size number of bytes from the stream.
If size is not defined, return all bytes of the stream
up to EOF.
"""
if size is None:
t = []
while True:
buf = self._read(self.bufsize)
if not buf:
break
t.append(buf)
buf = "".join(t)
else:
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:
buf = self.__read(self.bufsize)
if not buf:
break
buf = self.cmp.decompress(buf)
t.append(buf)
c += len(buf)
t = "".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 = "".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("\037\213\010"):
return "gz"
if self.buf.startswith("BZh91"):
return "bz2"
return "tar"
def close(self):
self.fileobj.close()
# class StreamProxy
#------------------------
# Extraction file object
#------------------------
class ExFileObject(object):
"""File-like object for reading an archive member.
Is returned by TarFile.extractfile(). Support for
sparse files included.
"""
def __init__(self, tarfile, tarinfo):
self.fileobj = tarfile.fileobj
self.name = tarinfo.name
self.mode = "r"
self.closed = False
self.offset = tarinfo.offset_data
self.size = tarinfo.size
self.pos = 0L
self.linebuffer = ""
if tarinfo.issparse():
self.sparse = tarinfo.sparse
self.read = self._readsparse
else:
self.read = self._readnormal
def __read(self, size):
"""Overloadable read method.
"""
return self.fileobj.read(size)
def readline(self, size=-1):
"""Read a line with approx. size. If size is negative,
read a whole line. readline() and read() must not
be mixed up (!).
"""
if size < 0:
size = sys.maxint
nl = self.linebuffer.find("\n")
if nl >= 0:
nl = min(nl, size)
else:
size -= len(self.linebuffer)
while (nl < 0 and size > 0):
buf = self.read(min(size, 100))
if not buf:
break
self.linebuffer += buf
size -= len(buf)
nl = self.linebuffer.find("\n")
if nl == -1:
s = self.linebuffer
self.linebuffer = ""
return s
buf = self.linebuffer[:nl]
self.linebuffer = self.linebuffer[nl + 1:]
while buf[-1:] == "\r":
buf = buf[:-1]
return buf + "\n"
def readlines(self):
"""Return a list with all (following) lines.
"""
result = []
while True:
line = self.readline()
if not line: break
result.append(line)
return result
def _readnormal(self, size=None):
"""Read operation for regular files.
"""
if self.closed:
raise ValueError, "file is closed"
self.fileobj.seek(self.offset + self.pos)
bytesleft = self.size - self.pos
if size is None:
bytestoread = bytesleft
else:
bytestoread = min(size, bytesleft)
self.pos += bytestoread
return self.__read(bytestoread)
def _readsparse(self, size=None):
"""Read operation for sparse files.
"""
if self.closed:
raise ValueError, "file is closed"
if size is None:
size = self.size - self.pos
data = []
while size > 0:
buf = self._readsparsesection(size)
if not buf:
break
size -= len(buf)
data.append(buf)
return "".join(data)
def _readsparsesection(self, size):
"""Read a single section of a sparse file.
"""
section = self.sparse.find(self.pos)
if section is None:
return ""
toread = min(size, section.offset + section.size - self.pos)
if isinstance(section, _data):
realpos = section.realpos + self.pos - section.offset
self.pos += toread
self.fileobj.seek(self.offset + realpos)
return self.__read(toread)
else:
self.pos += toread
return NUL * toread
def tell(self):
"""Return the current file position.
"""
return self.pos
def seek(self, pos, whence=0):
"""Seek to a position in the file.
"""
self.linebuffer = ""
if whence == 0:
self.pos = min(max(pos, 0), self.size)
if whence == 1:
if pos < 0:
self.pos = max(self.pos + pos, 0)
else:
self.pos = min(self.pos + pos, self.size)
if whence == 2:
self.pos = max(min(self.size + pos, self.size), 0)
def close(self):
"""Close the file object.
"""
self.closed = True
def __iter__(self):
"""Get an iterator over the file object.
"""
if self.closed:
raise ValueError("I/O operation on closed file")
return self
def next(self):
"""Get the next item from the file iterator.
"""
result = self.readline()
if not result:
raise StopIteration
return result
#class ExFileObject
#------------------
# Exported Classes
#------------------
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.
"""
def __init__(self, name=""):
"""Construct a TarInfo object. name is the optional name
of the member.
"""
self.name = name # member name (dirnames must end with '/')
self.mode = 0666 # 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" # user name
self.gname = "group" # group name
self.devmajor = 0 #-
self.devminor = 0 #-for use with CHRTYPE and BLKTYPE
self.prefix = "" # prefix to filename or holding information
# about sparse files
self.offset = 0 # the tar header starts here
self.offset_data = 0 # the file's data starts here
def __repr__(self):
return "<%s %r at %#x>" % (self.__class__.__name__,self.name,id(self))
@classmethod
def frombuf(cls, buf):
"""Construct a TarInfo object from a 512 byte string buffer.
"""
tarinfo = cls()
tarinfo.name = nts(buf[0:100])
tarinfo.mode = int(buf[100:108], 8)
tarinfo.uid = int(buf[108:116],8)
tarinfo.gid = int(buf[116:124],8)
# There are two possible codings for the size field we
# have to discriminate, see comment in tobuf() below.
if buf[124] != chr(0200):
tarinfo.size = long(buf[124:136], 8)
else:
tarinfo.size = 0L
for i in range(11):
tarinfo.size <<= 8
tarinfo.size += ord(buf[125 + i])
tarinfo.mtime = long(buf[136:148], 8)
tarinfo.chksum = int(buf[148:156], 8)
tarinfo.type = buf[156:157]
tarinfo.linkname = nts(buf[157:257])
tarinfo.uname = nts(buf[265:297])
tarinfo.gname = nts(buf[297:329])
try:
tarinfo.devmajor = int(buf[329:337], 8)
tarinfo.devminor = int(buf[337:345], 8)
except ValueError:
tarinfo.devmajor = tarinfo.devmajor = 0
tarinfo.prefix = buf[345:500]
# Some old tar programs represent a directory as a regular
# file with a trailing slash.
if tarinfo.isreg() and tarinfo.name.endswith("/"):
tarinfo.type = DIRTYPE
# The prefix field is used for filenames > 100 in
# the POSIX standard.
# name = prefix + '/' + name
if tarinfo.type != GNUTYPE_SPARSE:
tarinfo.name = normpath(os.path.join(nts(tarinfo.prefix), tarinfo.name))
# Directory names should have a '/' at the end.
if tarinfo.isdir():
tarinfo.name += "/"
return tarinfo
def tobuf(self):
"""Return a tar header block as a 512 byte string.
"""
# Prefer the size to be encoded as 11 octal ascii digits
# which is the most portable. If the size exceeds this
# limit (>= 8 GB), encode it as an 88-bit value which is
# a GNU tar feature.
if self.size <= MAXSIZE_MEMBER:
size = "%011o" % self.size
else:
s = self.size
size = ""
for i in range(11):
size = chr(s & 0377) + size
s >>= 8
size = chr(0200) + size
# The following code was contributed by Detlef Lannert.
parts = []
for value, fieldsize in (
(self.name, 100),
("%07o" % (self.mode & 07777), 8),
("%07o" % self.uid, 8),
("%07o" % self.gid, 8),
(size, 12),
("%011o" % self.mtime, 12),
(" ", 8),
(self.type, 1),
(self.linkname, 100),
(MAGIC, 6),
(VERSION, 2),
(self.uname, 32),
(self.gname, 32),
("%07o" % self.devmajor, 8),
("%07o" % self.devminor, 8),
(self.prefix, 155)
):
l = len(value)
parts.append(value[:fieldsize] + (fieldsize - l) * NUL)
buf = "".join(parts)
chksum = calc_chksum(buf)
buf = buf[:148] + "%06o\0" % chksum + buf[155:]
buf += (BLOCKSIZE - len(buf)) * NUL
self.buf = buf
return buf
def isreg(self):
return self.type in REGULAR_TYPES
def isfile(self):
return self.isreg()
def isdir(self):
return self.type == DIRTYPE
def issym(self):
return self.type == SYMTYPE
def islnk(self):
return self.type == LNKTYPE
def ischr(self):
return self.type == CHRTYPE
def isblk(self):
return self.type == BLKTYPE
def isfifo(self):
return self.type == FIFOTYPE
def issparse(self):
return self.type == GNUTYPE_SPARSE
def isdev(self):
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 = 0 # If 0, fatal errors only appear in debug
# messages (if debug >= 0). If > 0, errors
# are passed to the caller as exceptions.
posix = False # If True, generates POSIX.1-1990-compliant
# archives (no GNU extensions!)
fileobject = ExFileObject
def __init__(self, name=None, mode="r", fileobj=None):
"""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.
"""
self.name = name
if len(mode) > 1 or mode not in "raw":
raise ValueError, "mode must be 'r', 'a' or 'w'"
self._mode = mode
self.mode = {"r": "rb", "a": "r+b", "w": "wb"}[mode]
if not fileobj:
fileobj = file(self.name, self.mode)
self._extfileobj = False
else:
if self.name is None and hasattr(fileobj, "name"):
self.name = fileobj.name
if hasattr(fileobj, "mode"):
self.mode = fileobj.mode
self._extfileobj = True
self.fileobj = fileobj
# Init datastructures
self.closed = False
self.members = [] # list of members as TarInfo objects
self._loaded = False # flag if all members have been read
self.offset = 0L # current position in the archive file
self.inodes = {} # dictionary caching the inodes of
# archive members already added
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.
self.firstmember = None
while True:
try:
tarinfo = self.next()
except ReadError:
self.fileobj.seek(0)
break
if tarinfo is None:
self.fileobj.seek(- BLOCKSIZE, 1)
break
if self._mode in "aw":
self._loaded = True
#--------------------------------------------------------------------------
# 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=20*512):
"""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
'a' or 'a:' open for appending
'w' or 'w:' open for writing without compression
'w:gz' open for writing with gzip compression
'w:bz2' open for writing with bzip2 compression
'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
'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
"""
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.
for comptype in cls.OPEN_METH:
func = getattr(cls, cls.OPEN_METH[comptype])
try:
return func(name, "r", fileobj)
except (ReadError, CompressionError):
continue
raise ReadError, "file could not be opened successfully"
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)
elif "|" in mode:
filemode, comptype = mode.split("|", 1)
filemode = filemode or "r"
comptype = comptype or "tar"
if filemode not in "rw":
raise ValueError, "mode must be 'r' or 'w'"
t = cls(name, filemode,
_Stream(name, filemode, comptype, fileobj, bufsize))
t._extfileobj = False
return t
elif mode in "aw":
return cls.taropen(name, mode, fileobj)
raise ValueError, "undiscernible mode"
@classmethod
def taropen(cls, name, mode="r", fileobj=None):
"""Open uncompressed tar archive name for reading or writing.
"""
if len(mode) > 1 or mode not in "raw":
raise ValueError, "mode must be 'r', 'a' or 'w'"
return cls(name, mode, fileobj)
@classmethod
def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9):
"""Open gzip compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if len(mode) > 1 or mode not in "rw":
raise ValueError, "mode must be 'r' or 'w'"
try:
import gzip
gzip.GzipFile
except (ImportError, AttributeError):
raise CompressionError, "gzip module is not available"
pre, ext = os.path.splitext(name)
pre = os.path.basename(pre)
if ext == ".tgz":
ext = ".tar"
if ext == ".gz":
ext = ""
tarname = pre + ext
if fileobj is None:
fileobj = file(name, mode + "b")
if mode != "r":
name = tarname
try:
t = cls.taropen(tarname, mode,
gzip.GzipFile(name, mode, compresslevel, fileobj)
)
except IOError:
raise ReadError, "not a gzip file"
t._extfileobj = False
return t
@classmethod
def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9):
"""Open bzip2 compressed tar archive name for reading or writing.
Appending is not allowed.
"""
if len(mode) > 1 or mode not in "rw":
raise ValueError, "mode must be 'r' or 'w'."
try:
import bz2
except ImportError:
raise CompressionError, "bz2 module is not available"
pre, ext = os.path.splitext(name)
pre = os.path.basename(pre)
if ext == ".tbz2":
ext = ".tar"
if ext == ".bz2":
ext = ""
tarname = pre + ext
if fileobj is not None:
raise ValueError, "no support for external file objects"
try:
t = cls.taropen(tarname, mode, bz2.BZ2File(name, mode, compresslevel=compresslevel))
except IOError:
raise ReadError, "not a bzip2 file"
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
}
#--------------------------------------------------------------------------
# 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
if self._mode in "aw":
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))
if not self._extfileobj:
self.fileobj.close()
self.closed = True
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 occurence is assumed to be the
most up-to-date version.
"""
tarinfo = self._getmember(name)
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 for either the file `name' or the file
object `fileobj' (using os.fstat on its file descriptor). You can
modify some of the TarInfo's attributes before you add it using
addfile(). If given, `arcname' specifies an alternative name for the
file in the archive.
"""
self._check("aw")
# 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
arcname = normpath(arcname)
drv, arcname = os.path.splitdrive(arcname)
while arcname[0:1] == "/":
arcname = arcname[1:]
# Now, fill the TarInfo object with
# information specific for the file.
tarinfo = TarInfo()
# Use os.stat or os.lstat, depending on platform
# and if symlinks shall be resolved.
if fileobj is None:
if hasattr(os, "lstat") and 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:
# 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
if arcname[-1:] != "/":
arcname += "/"
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 stat.S_ISREG(stmd):
tarinfo.size = statres.st_size
else:
tarinfo.size = 0L
tarinfo.mtime = statres.st_mtime
tarinfo.type = type
tarinfo.linkname = linkname
if pwd:
try:
tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
except KeyError:
pass
if grp:
try:
tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
except KeyError:
pass
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):
"""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.
"""
self._check()
for tarinfo in self:
if verbose:
print filemode(tarinfo.mode),
print "%s/%s" % (tarinfo.uname or tarinfo.uid,
tarinfo.gname or tarinfo.gid),
if tarinfo.ischr() or tarinfo.isblk():
print "%10s" % ("%d,%d" \
% (tarinfo.devmajor, tarinfo.devminor)),
else:
print "%10d" % tarinfo.size,
print "%d-%02d-%02d %02d:%02d:%02d" \
% time.localtime(tarinfo.mtime)[:6],
print tarinfo.name,
if verbose:
if tarinfo.issym():
print "->", tarinfo.linkname,
if tarinfo.islnk():
print "link to", tarinfo.linkname,
print
def add(self, name, arcname=None, recursive=True):
"""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.
"""
self._check("aw")
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) == os.path.abspath(self.name):
self._dbg(2, "tarfile: Skipped %r" % name)
return
# Special case: The user wants to add the current
# working directory.
if name == ".":
if recursive:
if arcname == ".":
arcname = ""
for f in os.listdir("."):
self.add(f, os.path.join(arcname, f))
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
# Append the tar header and data to the archive.
if tarinfo.isreg():
f = file(name, "rb")
self.addfile(tarinfo, f)
f.close()
elif tarinfo.isdir():
self.addfile(tarinfo)
if recursive:
for f in os.listdir(name):
self.add(os.path.join(name, f), os.path.join(arcname, f))
else:
self.addfile(tarinfo)
def addfile(self, tarinfo, fileobj=None):
"""Add the TarInfo object `tarinfo' to the archive. If `fileobj' is
given, tarinfo.size bytes are read from it and added to the archive.
You can create TarInfo objects using gettarinfo().
On Windows platforms, `fileobj' should always be opened with mode
'rb' to avoid irritation about the file size.
"""
self._check("aw")
tarinfo.name = normpath(tarinfo.name)
if tarinfo.isdir():
# directories should end with '/'
tarinfo.name += "/"
if tarinfo.linkname:
tarinfo.linkname = normpath(tarinfo.linkname)
if tarinfo.size > MAXSIZE_MEMBER:
if self.posix:
raise ValueError, "file is too large (>= 8 GB)"
else:
self._dbg(2, "tarfile: Created GNU tar largefile header")
if len(tarinfo.linkname) > LENGTH_LINK:
if self.posix:
raise ValueError, "linkname is too long (>%d)" \
% (LENGTH_LINK)
else:
self._create_gnulong(tarinfo.linkname, GNUTYPE_LONGLINK)
tarinfo.linkname = tarinfo.linkname[:LENGTH_LINK -1]
self._dbg(2, "tarfile: Created GNU tar extension LONGLINK")
if len(tarinfo.name) > LENGTH_NAME:
if self.posix:
prefix = tarinfo.name[:LENGTH_PREFIX + 1]
while prefix and prefix[-1] != "/":
prefix = prefix[:-1]
name = tarinfo.name[len(prefix):]
prefix = prefix[:-1]
if not prefix or len(name) > LENGTH_NAME:
raise ValueError, "name is too long (>%d)" \
% (LENGTH_NAME)
tarinfo.name = name
tarinfo.prefix = prefix
else:
self._create_gnulong(tarinfo.name, GNUTYPE_LONGNAME)
tarinfo.name = tarinfo.name[:LENGTH_NAME - 1]
self._dbg(2, "tarfile: Created GNU tar extension LONGNAME")
self.fileobj.write(tarinfo.tobuf())
self.offset += BLOCKSIZE
# If there's data to follow, append it.
if fileobj is not None:
copyfileobj(fileobj, self.fileobj, tarinfo.size)
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 extractall(self, path=".", members=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().
"""
directories = []
if members is None:
members = self
for tarinfo in members:
if tarinfo.isdir():
# Extract directory with a safe mode, so that
# all files below can be extracted as well.
try:
os.makedirs(os.path.join(path, tarinfo.name), 0777)
except EnvironmentError:
pass
directories.append(tarinfo)
else:
self.extract(tarinfo, path)
# Reverse sort directories.
directories.sort(lambda a, b: cmp(a.name, b.name))
directories.reverse()
# Set correct owner, mtime and filemode on directories.
for tarinfo in directories:
path = os.path.join(path, tarinfo.name)
try:
self.chown(tarinfo, path)
self.utime(tarinfo, path)
self.chmod(tarinfo, path)
except ExtractError, e:
if self.errorlevel > 1:
raise
else:
self._dbg(1, "tarfile: %s" % e)
def extract(self, member, path=""):
"""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'.
"""
self._check("r")
if isinstance(member, TarInfo):
tarinfo = member
else:
tarinfo = self.getmember(member)
# Prepare the link target for makelink().
if tarinfo.islnk():
tarinfo._link_target = os.path.join(path, tarinfo.linkname)
try:
self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
except EnvironmentError, e:
if self.errorlevel > 0:
raise
else:
if e.filename is None:
self._dbg(1, "tarfile: %s" % e.strerror)
else:
self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
except ExtractError, e:
if self.errorlevel > 1:
raise
else:
self._dbg(1, "tarfile: %s" % 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, a
file-like object is returned. If `member' is a link, a file-like
object is constructed from the link's target. If `member' is none of
the above, None is returned.
The file-like object is read-only and provides the following
methods: read(), readline(), readlines(), seek() and tell()
"""
self._check("r")
if isinstance(member, TarInfo):
tarinfo = member
else:
tarinfo = self.getmember(member)
if tarinfo.isreg():
return self.fileobject(self, tarinfo)
elif tarinfo.type not in SUPPORTED_TYPES:
# If a member's type is unknown, it is treated as a
# regular file.
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._getmember(tarinfo.linkname,
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):
"""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.
if targetpath[-1:] == "/":
targetpath = targetpath[:-1]
targetpath = os.path.normpath(targetpath)
# Create all upper directories.
upperdirs = os.path.dirname(targetpath)
if upperdirs and not os.path.exists(upperdirs):
ti = TarInfo()
ti.name = upperdirs
ti.type = DIRTYPE
ti.mode = 0777
ti.mtime = tarinfo.mtime
ti.uid = tarinfo.uid
ti.gid = tarinfo.gid
ti.uname = tarinfo.uname
ti.gname = tarinfo.gname
try:
self._extract_member(ti, ti.name)
except:
pass
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)
self.chown(tarinfo, targetpath)
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:
os.mkdir(targetpath)
except EnvironmentError, e:
if e.errno != errno.EEXIST:
raise
def makefile(self, tarinfo, targetpath):
"""Make a file called targetpath.
"""
source = self.extractfile(tarinfo)
target = file(targetpath, "wb")
copyfileobj(source, target)
source.close()
target.close()
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 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.
"""
linkpath = tarinfo.linkname
try:
if tarinfo.issym():
os.symlink(linkpath, targetpath)
else:
# See extract().
os.link(tarinfo._link_target, targetpath)
except AttributeError:
if tarinfo.issym():
linkpath = os.path.join(os.path.dirname(tarinfo.name),
linkpath)
linkpath = normpath(linkpath)
try:
self._extract_member(self.getmember(linkpath), targetpath)
except (EnvironmentError, KeyError), e:
linkpath = os.path.normpath(linkpath)
try:
shutil.copy2(linkpath, targetpath)
except EnvironmentError, e:
raise IOError, "link could not be created"
def chown(self, tarinfo, targetpath):
"""Set owner of targetpath according to tarinfo.
"""
if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
# We have to be root to do so.
try:
g = grp.getgrnam(tarinfo.gname)[2]
except KeyError:
try:
g = grp.getgrgid(tarinfo.gid)[2]
except KeyError:
g = os.getgid()
try:
u = pwd.getpwnam(tarinfo.uname)[2]
except KeyError:
try:
u = pwd.getpwuid(tarinfo.uid)[2]
except KeyError:
u = os.getuid()
try:
if tarinfo.issym() and hasattr(os, "lchown"):
os.lchown(targetpath, u, g)
else:
if sys.platform != "os2emx":
os.chown(targetpath, u, g)
except EnvironmentError, e:
raise ExtractError, "could not change owner"
def chmod(self, tarinfo, targetpath):
"""Set file permissions of targetpath according to tarinfo.
"""
if hasattr(os, 'chmod'):
try:
os.chmod(targetpath, tarinfo.mode)
except EnvironmentError, e:
raise ExtractError, "could not change mode"
def utime(self, tarinfo, targetpath):
"""Set modification time of targetpath according to tarinfo.
"""
if not hasattr(os, 'utime'):
return
if sys.platform == "win32" and tarinfo.isdir():
# According to msdn.microsoft.com, it is an error (EACCES)
# to use utime() on directories.
return
try:
os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
except EnvironmentError, e:
raise ExtractError, "could not change modification time"
#--------------------------------------------------------------------------
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
# Read the next block.
self.fileobj.seek(self.offset)
while True:
buf = self.fileobj.read(BLOCKSIZE)
if not buf:
return None
try:
tarinfo = TarInfo.frombuf(buf)
except ValueError:
if self.ignore_zeros:
if buf.count(NUL) == BLOCKSIZE:
adj = "empty"
else:
adj = "invalid"
self._dbg(2, "0x%X: %s block" % (self.offset, adj))
self.offset += BLOCKSIZE
continue
else:
# Block is empty or unreadable.
if self.offset == 0:
# If the first block is invalid. That does not
# look like a tar archive we can handle.
raise ReadError,"empty, unreadable or compressed file"
return None
break
# We shouldn't rely on this checksum, because some tar programs
# calculate it differently and it is merely validating the
# header block. We could just as well skip this part, which would
# have a slight effect on performance...
if tarinfo.chksum != calc_chksum(buf):
self._dbg(1, "tarfile: Bad Checksum %r" % tarinfo.name)
# Set the TarInfo object's offset to the current position of the
# TarFile and set self.offset to the position where the data blocks
# should begin.
tarinfo.offset = self.offset
self.offset += BLOCKSIZE
# Check if the TarInfo object has a typeflag for which a callback
# method is registered in the TYPE_METH. If so, then call it.
if tarinfo.type in self.TYPE_METH:
return self.TYPE_METH[tarinfo.type](self, tarinfo)
tarinfo.offset_data = self.offset
if tarinfo.isreg() or tarinfo.type not in SUPPORTED_TYPES:
# Skip the following data blocks.
self.offset += self._block(tarinfo.size)
self.members.append(tarinfo)
return tarinfo
#--------------------------------------------------------------------------
# Below are some methods which are called for special typeflags in the
# next() method, e.g. for unwrapping GNU longname/longlink blocks. They
# are registered in TYPE_METH below. You can register your own methods
# with this mapping.
# A registered method is called with a TarInfo object as only argument.
#
# During its execution the method MUST perform the following tasks:
# 1. set tarinfo.offset_data to the position where the data blocks begin,
# if there is data to follow.
# 2. set self.offset to the position where the next member's header will
# begin.
# 3. append the tarinfo object to self.members, if it is supposed to appear
# as a member of the TarFile object.
# 4. return tarinfo or another valid TarInfo object.
def proc_gnulong(self, tarinfo):
"""Evaluate the blocks that hold a GNU longname
or longlink member.
"""
buf = ""
count = tarinfo.size
while count > 0:
block = self.fileobj.read(BLOCKSIZE)
buf += block
self.offset += BLOCKSIZE
count -= BLOCKSIZE
# Fetch the next header
next = self.next()
next.offset = tarinfo.offset
if tarinfo.type == GNUTYPE_LONGNAME:
next.name = nts(buf)
elif tarinfo.type == GNUTYPE_LONGLINK:
next.linkname = nts(buf)
return next
def proc_sparse(self, tarinfo):
"""Analyze a GNU sparse header plus extra headers.
"""
buf = tarinfo.tobuf()
sp = _ringbuffer()
pos = 386
lastpos = 0L
realpos = 0L
# There are 4 possible sparse structs in the
# first header.
for i in xrange(4):
try:
offset = int(buf[pos:pos + 12], 8)
numbytes = int(buf[pos + 12:pos + 24], 8)
except ValueError:
break
if offset > lastpos:
sp.append(_hole(lastpos, offset - lastpos))
sp.append(_data(offset, numbytes, realpos))
realpos += numbytes
lastpos = offset + numbytes
pos += 24
isextended = ord(buf[482])
origsize = int(buf[483:495], 8)
# If the isextended flag is given,
# there are extra headers to process.
while isextended == 1:
buf = self.fileobj.read(BLOCKSIZE)
self.offset += BLOCKSIZE
pos = 0
for i in xrange(21):
try:
offset = int(buf[pos:pos + 12], 8)
numbytes = int(buf[pos + 12:pos + 24], 8)
except ValueError:
break
if offset > lastpos:
sp.append(_hole(lastpos, offset - lastpos))
sp.append(_data(offset, numbytes, realpos))
realpos += numbytes
lastpos = offset + numbytes
pos += 24
isextended = ord(buf[504])
if lastpos < origsize:
sp.append(_hole(lastpos, origsize - lastpos))
tarinfo.sparse = sp
tarinfo.offset_data = self.offset
self.offset += self._block(tarinfo.size)
tarinfo.size = origsize
self.members.append(tarinfo)
return tarinfo
# The type mapping for the next() method. The keys are single character
# strings, the typeflag. The values are methods which are called when
# next() encounters such a typeflag.
TYPE_METH = {
GNUTYPE_LONGNAME: proc_gnulong,
GNUTYPE_LONGLINK: proc_gnulong,
GNUTYPE_SPARSE: proc_sparse
}
#--------------------------------------------------------------------------
# Little helper methods:
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 _getmember(self, name, tarinfo=None):
"""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()
if tarinfo is None:
end = len(members)
else:
end = members.index(tarinfo)
for i in xrange(end - 1, -1, -1):
if name == members[i].name:
return members[i]
def _load(self):
"""Read through the entire archive file and look for readable
members.
"""
while True:
tarinfo = self.next()
if tarinfo is None:
break
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 IOError, "%s is closed" % self.__class__.__name__
if mode is not None and self._mode not in mode:
raise IOError, "bad operation for mode %r" % self._mode
def __iter__(self):
"""Provide an iterator object.
"""
if self._loaded:
return iter(self.members)
else:
return TarIter(self)
def _create_gnulong(self, name, type):
"""Write a GNU longname/longlink member to the TarFile.
It consists of an extended tar header, with the length
of the longname as size, followed by data blocks,
which contain the longname as a null terminated string.
"""
name += NUL
tarinfo = TarInfo()
tarinfo.name = "././@LongLink"
tarinfo.type = type
tarinfo.mode = 0
tarinfo.size = len(name)
# write extended header
self.fileobj.write(tarinfo.tobuf())
self.offset += BLOCKSIZE
# write name blocks
self.fileobj.write(name)
blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
if remainder > 0:
self.fileobj.write(NUL * (BLOCKSIZE - remainder))
blocks += 1
self.offset += blocks * BLOCKSIZE
def _dbg(self, level, msg):
"""Write debugging output to sys.stderr.
"""
if level <= self.debug:
print >> sys.stderr, msg
# class TarFile
class TarIter:
"""Iterator Class.
for tarinfo in TarFile(...):
suite...
"""
def __init__(self, tarfile):
"""Construct a TarIter object.
"""
self.tarfile = tarfile
self.index = 0
def __iter__(self):
"""Return iterator object.
"""
return self
def next(self):
"""Return the next item using TarFile's next() method.
When all members have been read, set TarFile as _loaded.
"""
# Fix for SF #1100429: Under rare circumstances it can
# happen that getmembers() is called during iteration,
# which will cause TarIter to stop prematurely.
if not self.tarfile._loaded:
tarinfo = self.tarfile.next()
if not tarinfo:
self.tarfile._loaded = True
raise StopIteration
else:
try:
tarinfo = self.tarfile.members[self.index]
except IndexError:
raise StopIteration
self.index += 1
return tarinfo
# Helper classes for sparse file support
class _section:
"""Base class for _data and _hole.
"""
def __init__(self, offset, size):
self.offset = offset
self.size = size
def __contains__(self, offset):
return self.offset <= offset < self.offset + self.size
class _data(_section):
"""Represent a data section in a sparse file.
"""
def __init__(self, offset, size, realpos):
_section.__init__(self, offset, size)
self.realpos = realpos
class _hole(_section):
"""Represent a hole section in a sparse file.
"""
pass
class _ringbuffer(list):
"""Ringbuffer class which increases performance
over a regular list.
"""
def __init__(self):
self.idx = 0
def find(self, offset):
idx = self.idx
while True:
item = self[idx]
if offset in item:
break
idx += 1
if idx == len(self):
idx = 0
if idx == self.idx:
# End of File
return None
self.idx = idx
return item
#---------------------------------------------
# zipfile compatible TarFile class
#---------------------------------------------
TAR_PLAIN = 0 # zipfile.ZIP_STORED
TAR_GZIPPED = 8 # zipfile.ZIP_DEFLATED
class TarFileCompat:
"""TarFile class compatible with standard module zipfile's
ZipFile class.
"""
def __init__(self, file, mode="r", compression=TAR_PLAIN):
if compression == TAR_PLAIN:
self.tarfile = TarFile.taropen(file, mode)
elif compression == TAR_GZIPPED:
self.tarfile = TarFile.gzopen(file, mode)
else:
raise ValueError, "unknown compression constant"
if mode[0:1] == "r":
members = self.tarfile.getmembers()
for m in members:
m.filename = m.name
m.file_size = m.size
m.date_time = time.gmtime(m.mtime)[:6]
def namelist(self):
return map(lambda m: m.name, self.infolist())
def infolist(self):
return filter(lambda m: m.type in REGULAR_TYPES,
self.tarfile.getmembers())
def printdir(self):
self.tarfile.list()
def testzip(self):
return
def getinfo(self, name):
return self.tarfile.getmember(name)
def read(self, name):
return self.tarfile.extractfile(self.tarfile.getmember(name)).read()
def write(self, filename, arcname=None, compress_type=None):
self.tarfile.add(filename, arcname)
def writestr(self, zinfo, bytes):
try:
from cStringIO import StringIO
except ImportError:
from StringIO import StringIO
import calendar
zinfo.name = zinfo.filename
zinfo.size = zinfo.file_size
zinfo.mtime = calendar.timegm(zinfo.date_time)
self.tarfile.addfile(zinfo, StringIO(bytes))
def close(self):
self.tarfile.close()
#class TarFileCompat
#--------------------
# exported functions
#--------------------
def is_tarfile(name):
"""Return True if name points to a tar archive that we
are able to handle, else return False.
"""
try:
t = open(name)
t.close()
return True
except TarError:
return False
open = TarFile.open
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