#!/usr/bin/env python # -*- coding: iso-8859-1 -*- #------------------------------------------------------------------- # tarfile.py #------------------------------------------------------------------- # Copyright (C) 2002 Lars Gustäbel # 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, "x", TSUID, "S", TUEXEC|TSUID, "s"), (TGREAD, "r"), (TGWRITE, "w"), (TGEXEC, "x", TSGID, "S", TGEXEC|TSGID, "s"), (TOREAD, "r"), (TOWRITE, "w"), (TOEXEC, "x", TSVTX, "T", TOEXEC|TSVTX, "t")) def filemode(mode): """Convert a file's mode to a string of the form -rwxrwxrwx. Used by TarFile.list() """ s = "" for t in filemode_table: while True: if mode & t[0] == t[0]: s += t[1] elif len(t) > 2: t = t[2:] continue else: s += "-" break return s 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, type, fileobj, bufsize): """Construct a _Stream object. """ self._extfileobj = True if fileobj is None: fileobj = _LowLevelFile(name, mode) self._extfileobj = False self.name = name or "" self.mode = mode self.type = type self.fileobj = fileobj self.bufsize = bufsize self.buf = "" self.pos = 0L self.closed = False if type == "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 type == "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 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(" 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.type != "tar": self.buf += self.cmp.flush() if self.mode == "w" and self.buf: self.fileobj.write(self.buf) self.buf = "" if self.type == "gz": self.fileobj.write(struct.pack("= 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.type == "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 #------------------------ # 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 #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)) 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] # 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() and tarinfo.name[-1:] != "/": tarinfo.name += "/" return tarinfo frombuf = classmethod(frombuf) 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. 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' 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 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 ":" 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 == "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 mode in "aw": return cls.taropen(name, mode, fileobj) raise ValueError, "undiscernible mode" open = classmethod(open) 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) taropen = classmethod(taropen) 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 gzopen = classmethod(gzopen) 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 bz2open = classmethod(bz2open) # 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 inode in self.inodes and not self.dereference: # 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_ISDIR(stmd): # For a directory, the size must be 0 tarinfo.size = 0 else: tarinfo.size = statres.st_size 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() if tarinfo.type in (LNKTYPE, SYMTYPE, FIFOTYPE, CHRTYPE, BLKTYPE): tarinfo.size = 0L self.addfile(tarinfo) if 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)) 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 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 it's 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) if tarinfo.isreg() and tarinfo.name[:-1] == "/": # some old tar programs don't know DIRTYPE tarinfo.type = DIRTYPE 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 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. """ tarinfo = self.tarfile.next() if not tarinfo: self.tarfile._loaded = True raise StopIteration 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 i in xrange(len(members)): m = members[i] 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): 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.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