Editing: tarfile.py
# -*- coding: iso-8859-1 -*- #------------------------------------------------------------------- # tarfile.py #------------------------------------------------------------------- # Copyright (C) 2002 Lars Gust�bel <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: 85213 $" # $Source$ version = "0.9.0" __author__ = "Lars Gust�bel (lars@gustaebel.de)" __date__ = "$Date$" __cvsid__ = "$Id$" __credits__ = "Gustavo Niemeyer, Niels Gust�bel, Richard Townsend." #--------- # Imports #--------- from __builtin__ import open as bltn_open import sys import os import shutil import stat import errno import time import struct import copy import re import operator 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 GNU_MAGIC = "ustar \0" # magic gnu tar string POSIX_MAGIC = "ustar\x0000" # magic posix tar string LENGTH_NAME = 100 # maximum length of a filename LENGTH_LINK = 100 # maximum length of a linkname LENGTH_PREFIX = 155 # maximum length of the prefix field REGTYPE = "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 longname GNUTYPE_LONGLINK = "K" # GNU tar longlink GNUTYPE_SPARSE = "S" # GNU tar sparse file XHDTYPE = "x" # POSIX.1-2001 extended header XGLTYPE = "g" # POSIX.1-2001 global header SOLARIS_XHDTYPE = "X" # Solaris extended header USTAR_FORMAT = 0 # POSIX.1-1988 (ustar) format GNU_FORMAT = 1 # GNU tar format PAX_FORMAT = 2 # POSIX.1-2001 (pax) format DEFAULT_FORMAT = GNU_FORMAT #--------------------------------------------------------- # tarfile constants #--------------------------------------------------------- # File types that tarfile supports: SUPPORTED_TYPES = (REGTYPE, AREGTYPE, LNKTYPE, SYMTYPE, DIRTYPE, FIFOTYPE, CONTTYPE, CHRTYPE, BLKTYPE, GNUTYPE_LONGNAME, GNUTYPE_LONGLINK, GNUTYPE_SPARSE) # File types that will be treated as a regular file. REGULAR_TYPES = (REGTYPE, AREGTYPE, CONTTYPE, GNUTYPE_SPARSE) # File types that are part of the GNU tar format. GNU_TYPES = (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK, GNUTYPE_SPARSE) # Fields from a pax header that override a TarInfo attribute. PAX_FIELDS = ("path", "linkpath", "size", "mtime", "uid", "gid", "uname", "gname") # Fields in a pax header that are numbers, all other fields # are treated as strings. PAX_NUMBER_FIELDS = { "atime": float, "ctime": float, "mtime": float, "uid": int, "gid": int, "size": int } #--------------------------------------------------------- # 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 #--------------------------------------------------------- # initialization #--------------------------------------------------------- ENCODING = sys.getfilesystemencoding() if ENCODING is None: ENCODING = sys.getdefaultencoding() #--------------------------------------------------------- # Some useful functions #--------------------------------------------------------- def stn(s, length): """Convert a python string to a null-terminated string buffer. """ return s[:length] + (length - len(s)) * NUL def nts(s): """Convert a null-terminated string field to a python string. """ # Use the string up to the first null char. p = s.find("\0") if p == -1: return s return s[:p] def nti(s): """Convert a number field to a python number. """ # There are two possible encodings for a number field, see # itn() below. if s[0] != chr(0200): try: n = int(nts(s).strip() or "0", 8) except ValueError: raise InvalidHeaderError("invalid header") else: n = 0L for i in xrange(len(s) - 1): n <<= 8 n += ord(s[i + 1]) return n def itn(n, digits=8, format=DEFAULT_FORMAT): """Convert a python number to a number field. """ # POSIX 1003.1-1988 requires numbers to be encoded as a string of # octal digits followed by a null-byte, this allows values up to # (8**(digits-1))-1. GNU tar allows storing numbers greater than # that if necessary. A leading 0200 byte indicates this particular # encoding, the following digits-1 bytes are a big-endian # representation. This allows values up to (256**(digits-1))-1. if 0 <= n < 8 ** (digits - 1): s = "%0*o" % (digits - 1, n) + NUL else: if format != GNU_FORMAT or n >= 256 ** (digits - 1): raise ValueError("overflow in number field") if n < 0: # XXX We mimic GNU tar's behaviour with negative numbers, # this could raise OverflowError. n = struct.unpack("L", struct.pack("l", n))[0] s = "" for i in xrange(digits - 1): s = chr(n & 0377) + s n >>= 8 s = chr(0200) + s return s def uts(s, encoding, errors): """Convert a unicode object to a string. """ if errors == "utf-8": # An extra error handler similar to the -o invalid=UTF-8 option # in POSIX.1-2001. Replace untranslatable characters with their # UTF-8 representation. try: return s.encode(encoding, "strict") except UnicodeEncodeError: x = [] for c in s: try: x.append(c.encode(encoding, "strict")) except UnicodeEncodeError: x.append(c.encode("utf8")) return "".join(x) else: return s.encode(encoding, errors) def calc_chksums(buf): """Calculate the checksum for a member's header by summing up all characters except for the chksum field which is treated as if it was filled with spaces. According to the GNU tar sources, some tars (Sun and NeXT) calculate chksum with signed char, which will be different if there are chars in the buffer with the high bit set. So we calculate two checksums, unsigned and signed. """ unsigned_chksum = 256 + sum(struct.unpack("148B", buf[:148]) + struct.unpack("356B", buf[156:512])) signed_chksum = 256 + sum(struct.unpack("148b", buf[:148]) + struct.unpack("356b", buf[156:512])) return unsigned_chksum, signed_chksum 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) class TarError(Exception): """Base exception.""" pass class ExtractError(TarError): """General exception for extract errors.""" pass class ReadError(TarError): """Exception for unreadable tar archives.""" pass class CompressionError(TarError): """Exception for unavailable compression methods.""" pass class StreamError(TarError): """Exception for unsupported operations on stream-like TarFiles.""" pass class HeaderError(TarError): """Base exception for header errors.""" pass class EmptyHeaderError(HeaderError): """Exception for empty headers.""" pass class TruncatedHeaderError(HeaderError): """Exception for truncated headers.""" pass class EOFHeaderError(HeaderError): """Exception for end of file headers.""" pass class InvalidHeaderError(HeaderError): """Exception for invalid headers.""" pass class SubsequentHeaderError(HeaderError): """Exception for missing and invalid extended headers.""" pass #--------------------------- # internal stream interface #--------------------------- class _LowLevelFile: """Low-level file object. Supports reading and writing. It is used instead of a regular file object for streaming access. """ def __init__(self, name, mode): mode = { "r": os.O_RDONLY, "w": os.O_WRONLY | os.O_CREAT | os.O_TRUNC, }[mode] if hasattr(os, "O_BINARY"): mode |= os.O_BINARY self.fd = os.open(name, mode, 0666) 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 try: if comptype == "gz": try: import zlib except ImportError: raise CompressionError("zlib module is not available") self.zlib = zlib self.crc = zlib.crc32("") & 0xffffffffL if mode == "r": self._init_read_gz() else: self._init_write_gz() elif 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() except: if not self._extfileobj: self.fileobj.close() self.closed = True raise def __del__(self): if hasattr(self, "closed") and not self.closed: self.close() def _init_write_gz(self): """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 type(self.name) is unicode: self.name = self.name.encode("iso-8859-1", "replace") 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) & 0xffffffffL self.pos += len(s) if self.comptype != "tar": s = self.cmp.compress(s) self.__write(s) def __write(self, s): """Write string s to the stream if a whole new block is ready to be written. """ self.buf += s while len(self.buf) > self.bufsize: self.fileobj.write(self.buf[:self.bufsize]) self.buf = self.buf[self.bufsize:] def close(self): """Close the _Stream object. No operation should be done on it afterwards. """ if self.closed: return self.closed = True try: if self.mode == "w" and self.comptype != "tar": self.buf += self.cmp.flush() if self.mode == "w" and self.buf: self.fileobj.write(self.buf) self.buf = "" if self.comptype == "gz": # The native zlib crc is an unsigned 32-bit integer, but # the Python wrapper implicitly casts that to a signed C # long. So, on a 32-bit box self.crc may "look negative", # while the same crc on a 64-bit box may "look positive". # To avoid irksome warnings from the `struct` module, force # it to look positive on all boxes. self.fileobj.write(struct.pack("<L", self.crc & 0xffffffffL)) self.fileobj.write(struct.pack("<L", self.pos & 0xffffFFFFL)) finally: if not self._extfileobj: self.fileobj.close() def _init_read_gz(self): """Initialize for reading a gzip compressed fileobj. """ self.cmp = self.zlib.decompressobj(-self.zlib.MAX_WBITS) self.dbuf = "" # 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 try: buf = self.cmp.decompress(buf) except IOError: raise ReadError("invalid compressed data") 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[0:3] == "BZh" and self.buf[4:10] == "1AY&SY": return "bz2" return "tar" def close(self): self.fileobj.close() # class StreamProxy class _BZ2Proxy(object): """Small proxy class that enables external file object support for "r:bz2" and "w:bz2" modes. This is actually a workaround for a limitation in bz2 module's BZ2File class which (unlike gzip.GzipFile) has no support for a file object argument. """ blocksize = 16 * 1024 def __init__(self, fileobj, mode): self.fileobj = fileobj self.mode = mode self.name = getattr(self.fileobj, "name", None) self.init() def init(self): import bz2 self.pos = 0 if self.mode == "r": self.bz2obj = bz2.BZ2Decompressor() self.fileobj.seek(0) self.buf = "" else: self.bz2obj = bz2.BZ2Compressor() def read(self, size): b = [self.buf] x = len(self.buf) while x < size: raw = self.fileobj.read(self.blocksize) if not raw: break data = self.bz2obj.decompress(raw) b.append(data) x += len(data) self.buf = "".join(b) buf = self.buf[:size] self.buf = self.buf[size:] self.pos += len(buf) return buf def seek(self, pos): if pos < self.pos: self.init() self.read(pos - self.pos) def tell(self): return self.pos def write(self, data): self.pos += len(data) raw = self.bz2obj.compress(data) self.fileobj.write(raw) def close(self): if self.mode == "w": raw = self.bz2obj.flush() self.fileobj.write(raw) # class _BZ2Proxy #------------------------ # Extraction file object #------------------------ class _FileInFile(object): """A thin wrapper around an existing file object that provides a part of its data as an individual file object. """ def __init__(self, fileobj, offset, size, sparse=None): self.fileobj = fileobj self.offset = offset self.size = size self.sparse = sparse self.position = 0 def tell(self): """Return the current file position. """ return self.position def seek(self, position): """Seek to a position in the file. """ self.position = position def read(self, size=None): """Read data from the file. """ if size is None: size = self.size - self.position else: size = min(size, self.size - self.position) if self.sparse is None: return self.readnormal(size) else: return self.readsparse(size) def __read(self, size): buf = self.fileobj.read(size) if len(buf) != size: raise ReadError("unexpected end of data") return buf def readnormal(self, size): """Read operation for regular files. """ self.fileobj.seek(self.offset + self.position) self.position += size return self.__read(size) def readsparse(self, size): """Read operation for sparse files. """ 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.position) if section is None: return "" size = min(size, section.offset + section.size - self.position) if isinstance(section, _data): realpos = section.realpos + self.position - section.offset self.fileobj.seek(self.offset + realpos) self.position += size return self.__read(size) else: self.position += size return NUL * size #class _FileInFile class ExFileObject(object): """File-like object for reading an archive member. Is returned by TarFile.extractfile(). """ blocksize = 1024 def __init__(self, tarfile, tarinfo): self.fileobj = _FileInFile(tarfile.fileobj, tarinfo.offset_data, tarinfo.size, getattr(tarinfo, "sparse", None)) self.name = tarinfo.name self.mode = "r" self.closed = False self.size = tarinfo.size self.position = 0 self.buffer = "" def read(self, size=None): """Read at most size bytes from the file. If size is not present or None, read all data until EOF is reached. """ if self.closed: raise ValueError("I/O operation on closed file") buf = "" if self.buffer: if size is None: buf = self.buffer self.buffer = "" else: buf = self.buffer[:size] self.buffer = self.buffer[size:] if size is None: buf += self.fileobj.read() else: buf += self.fileobj.read(size - len(buf)) self.position += len(buf) return buf def readline(self, size=-1): """Read one entire line from the file. If size is present and non-negative, return a string with at most that size, which may be an incomplete line. """ if self.closed: raise ValueError("I/O operation on closed file") if "\n" in self.buffer: pos = self.buffer.find("\n") + 1 else: buffers = [self.buffer] while True: buf = self.fileobj.read(self.blocksize) buffers.append(buf) if not buf or "\n" in buf: self.buffer = "".join(buffers) pos = self.buffer.find("\n") + 1 if pos == 0: # no newline found. pos = len(self.buffer) break if size != -1: pos = min(size, pos) buf = self.buffer[:pos] self.buffer = self.buffer[pos:] self.position += len(buf) return buf def readlines(self): """Return a list with all remaining lines. """ result = [] while True: line = self.readline() if not line: break result.append(line) return result def tell(self): """Return the current file position. """ if self.closed: raise ValueError("I/O operation on closed file") return self.position def seek(self, pos, whence=os.SEEK_SET): """Seek to a position in the file. """ if self.closed: raise ValueError("I/O operation on closed file") if whence == os.SEEK_SET: self.position = min(max(pos, 0), self.size) elif whence == os.SEEK_CUR: if pos < 0: self.position = max(self.position + pos, 0) else: self.position = min(self.position + pos, self.size) elif whence == os.SEEK_END: self.position = max(min(self.size + pos, self.size), 0) else: raise ValueError("Invalid argument") self.buffer = "" self.fileobj.seek(self.position) def close(self): """Close the file object. """ self.closed = True def __iter__(self): """Get an iterator over the file's lines. """ while True: line = self.readline() if not line: break yield line #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 self.mode = 0644 # file permissions self.uid = 0 # user id self.gid = 0 # group id self.size = 0 # file size self.mtime = 0 # modification time self.chksum = 0 # header checksum self.type = REGTYPE # member type self.linkname = "" # link name self.uname = "" # user name self.gname = "" # group name self.devmajor = 0 # device major number self.devminor = 0 # device minor number self.offset = 0 # the tar header starts here self.offset_data = 0 # the file's data starts here self.pax_headers = {} # pax header information # In pax headers the "name" and "linkname" field are called # "path" and "linkpath". def _getpath(self): return self.name def _setpath(self, name): self.name = name path = property(_getpath, _setpath) def _getlinkpath(self): return self.linkname def _setlinkpath(self, linkname): self.linkname = linkname linkpath = property(_getlinkpath, _setlinkpath) def __repr__(self): return "<%s %r at %#x>" % (self.__class__.__name__,self.name,id(self)) def get_info(self, encoding, errors): """Return the TarInfo's attributes as a dictionary. """ info = { "name": self.name, "mode": self.mode & 07777, "uid": self.uid, "gid": self.gid, "size": self.size, "mtime": self.mtime, "chksum": self.chksum, "type": self.type, "linkname": self.linkname, "uname": self.uname, "gname": self.gname, "devmajor": self.devmajor, "devminor": self.devminor } if info["type"] == DIRTYPE and not info["name"].endswith("/"): info["name"] += "/" for key in ("name", "linkname", "uname", "gname"): if type(info[key]) is unicode: info[key] = info[key].encode(encoding, errors) return info def tobuf(self, format=DEFAULT_FORMAT, encoding=ENCODING, errors="strict"): """Return a tar header as a string of 512 byte blocks. """ info = self.get_info(encoding, errors) if format == USTAR_FORMAT: return self.create_ustar_header(info) elif format == GNU_FORMAT: return self.create_gnu_header(info) elif format == PAX_FORMAT: return self.create_pax_header(info, encoding, errors) else: raise ValueError("invalid format") def create_ustar_header(self, info): """Return the object as a ustar header block. """ info["magic"] = POSIX_MAGIC if len(info["linkname"]) > LENGTH_LINK: raise ValueError("linkname is too long") if len(info["name"]) > LENGTH_NAME: info["prefix"], info["name"] = self._posix_split_name(info["name"]) return self._create_header(info, USTAR_FORMAT) def create_gnu_header(self, info): """Return the object as a GNU header block sequence. """ info["magic"] = GNU_MAGIC buf = "" if len(info["linkname"]) > LENGTH_LINK: buf += self._create_gnu_long_header(info["linkname"], GNUTYPE_LONGLINK) if len(info["name"]) > LENGTH_NAME: buf += self._create_gnu_long_header(info["name"], GNUTYPE_LONGNAME) return buf + self._create_header(info, GNU_FORMAT) def create_pax_header(self, info, encoding, errors): """Return the object as a ustar header block. If it cannot be represented this way, prepend a pax extended header sequence with supplement information. """ info["magic"] = POSIX_MAGIC pax_headers = self.pax_headers.copy() # Test string fields for values that exceed the field length or cannot # be represented in ASCII encoding. for name, hname, length in ( ("name", "path", LENGTH_NAME), ("linkname", "linkpath", LENGTH_LINK), ("uname", "uname", 32), ("gname", "gname", 32)): if hname in pax_headers: # The pax header has priority. continue val = info[name].decode(encoding, errors) # Try to encode the string as ASCII. try: val.encode("ascii") except UnicodeEncodeError: pax_headers[hname] = val continue if len(info[name]) > length: pax_headers[hname] = val # Test number fields for values that exceed the field limit or values # that like to be stored as float. for name, digits in (("uid", 8), ("gid", 8), ("size", 12), ("mtime", 12)): if name in pax_headers: # The pax header has priority. Avoid overflow. info[name] = 0 continue val = info[name] if not 0 <= val < 8 ** (digits - 1) or isinstance(val, float): pax_headers[name] = unicode(val) info[name] = 0 # Create a pax extended header if necessary. if pax_headers: buf = self._create_pax_generic_header(pax_headers) else: buf = "" return buf + self._create_header(info, USTAR_FORMAT) @classmethod def create_pax_global_header(cls, pax_headers): """Return the object as a pax global header block sequence. """ return cls._create_pax_generic_header(pax_headers, type=XGLTYPE) def _posix_split_name(self, name): """Split a name longer than 100 chars into a prefix and a name part. """ prefix = name[:LENGTH_PREFIX + 1] while prefix and prefix[-1] != "/": prefix = prefix[:-1] name = name[len(prefix):] prefix = prefix[:-1] if not prefix or len(name) > LENGTH_NAME: raise ValueError("name is too long") return prefix, name @staticmethod def _create_header(info, format): """Return a header block. info is a dictionary with file information, format must be one of the *_FORMAT constants. """ parts = [ stn(info.get("name", ""), 100), itn(info.get("mode", 0) & 07777, 8, format), itn(info.get("uid", 0), 8, format), itn(info.get("gid", 0), 8, format), itn(info.get("size", 0), 12, format), itn(info.get("mtime", 0), 12, format), " ", # checksum field info.get("type", REGTYPE), stn(info.get("linkname", ""), 100), stn(info.get("magic", POSIX_MAGIC), 8), stn(info.get("uname", ""), 32), stn(info.get("gname", ""), 32), itn(info.get("devmajor", 0), 8, format), itn(info.get("devminor", 0), 8, format), stn(info.get("prefix", ""), 155) ] buf = struct.pack("%ds" % BLOCKSIZE, "".join(parts)) chksum = calc_chksums(buf[-BLOCKSIZE:])[0] buf = buf[:-364] + "%06o\0" % chksum + buf[-357:] return buf @staticmethod def _create_payload(payload): """Return the string payload filled with zero bytes up to the next 512 byte border. """ blocks, remainder = divmod(len(payload), BLOCKSIZE) if remainder > 0: payload += (BLOCKSIZE - remainder) * NUL return payload @classmethod def _create_gnu_long_header(cls, name, type): """Return a GNUTYPE_LONGNAME or GNUTYPE_LONGLINK sequence for name. """ name += NUL info = {} info["name"] = "././@LongLink" info["type"] = type info["size"] = len(name) info["magic"] = GNU_MAGIC # create extended header + name blocks. return cls._create_header(info, USTAR_FORMAT) + \ cls._create_payload(name) @classmethod def _create_pax_generic_header(cls, pax_headers, type=XHDTYPE): """Return a POSIX.1-2001 extended or global header sequence that contains a list of keyword, value pairs. The values must be unicode objects. """ records = [] for keyword, value in pax_headers.iteritems(): keyword = keyword.encode("utf8") value = value.encode("utf8") l = len(keyword) + len(value) + 3 # ' ' + '=' + '\n' n = p = 0 while True: n = l + len(str(p)) if n == p: break p = n records.append("%d %s=%s\n" % (p, keyword, value)) records = "".join(records) # We use a hardcoded "././@PaxHeader" name like star does # instead of the one that POSIX recommends. info = {} info["name"] = "././@PaxHeader" info["type"] = type info["size"] = len(records) info["magic"] = POSIX_MAGIC # Create pax header + record blocks. return cls._create_header(info, USTAR_FORMAT) + \ cls._create_payload(records) @classmethod def frombuf(cls, buf): """Construct a TarInfo object from a 512 byte string buffer. """ if len(buf) == 0: raise EmptyHeaderError("empty header") if len(buf) != BLOCKSIZE: raise TruncatedHeaderError("truncated header") if buf.count(NUL) == BLOCKSIZE: raise EOFHeaderError("end of file header") chksum = nti(buf[148:156]) if chksum not in calc_chksums(buf): raise InvalidHeaderError("bad checksum") obj = cls() obj.buf = buf obj.name = nts(buf[0:100]) obj.mode = nti(buf[100:108]) obj.uid = nti(buf[108:116]) obj.gid = nti(buf[116:124]) obj.size = nti(buf[124:136]) obj.mtime = nti(buf[136:148]) obj.chksum = chksum obj.type = buf[156:157] obj.linkname = nts(buf[157:257]) obj.uname = nts(buf[265:297]) obj.gname = nts(buf[297:329]) obj.devmajor = nti(buf[329:337]) obj.devminor = nti(buf[337:345]) prefix = nts(buf[345:500]) # Old V7 tar format represents a directory as a regular # file with a trailing slash. if obj.type == AREGTYPE and obj.name.endswith("/"): obj.type = DIRTYPE # Remove redundant slashes from directories. if obj.isdir(): obj.name = obj.name.rstrip("/") # Reconstruct a ustar longname. if prefix and obj.type not in GNU_TYPES: obj.name = prefix + "/" + obj.name return obj @classmethod def fromtarfile(cls, tarfile): """Return the next TarInfo object from TarFile object tarfile. """ buf = tarfile.fileobj.read(BLOCKSIZE) obj = cls.frombuf(buf) obj.offset = tarfile.fileobj.tell() - BLOCKSIZE return obj._proc_member(tarfile) #-------------------------------------------------------------------------- # The following are methods that are called depending on the type of a # member. The entry point is _proc_member() which can be overridden in a # subclass to add custom _proc_*() methods. A _proc_*() method MUST # implement the following # operations: # 1. Set self.offset_data to the position where the data blocks begin, # if there is data that follows. # 2. Set tarfile.offset to the position where the next member's header will # begin. # 3. Return self or another valid TarInfo object. def _proc_member(self, tarfile): """Choose the right processing method depending on the type and call it. """ if self.type in (GNUTYPE_LONGNAME, GNUTYPE_LONGLINK): return self._proc_gnulong(tarfile) elif self.type == GNUTYPE_SPARSE: return self._proc_sparse(tarfile) elif self.type in (XHDTYPE, XGLTYPE, SOLARIS_XHDTYPE): return self._proc_pax(tarfile) else: return self._proc_builtin(tarfile) def _proc_builtin(self, tarfile): """Process a builtin type or an unknown type which will be treated as a regular file. """ self.offset_data = tarfile.fileobj.tell() offset = self.offset_data if self.isreg() or self.type not in SUPPORTED_TYPES: # Skip the following data blocks. offset += self._block(self.size) tarfile.offset = offset # Patch the TarInfo object with saved global # header information. self._apply_pax_info(tarfile.pax_headers, tarfile.encoding, tarfile.errors) return self def _proc_gnulong(self, tarfile): """Process the blocks that hold a GNU longname or longlink member. """ buf = tarfile.fileobj.read(self._block(self.size)) # Fetch the next header and process it. try: next = self.fromtarfile(tarfile) except HeaderError: raise SubsequentHeaderError("missing or bad subsequent header") # Patch the TarInfo object from the next header with # the longname information. next.offset = self.offset if self.type == GNUTYPE_LONGNAME: next.name = nts(buf) elif self.type == GNUTYPE_LONGLINK: next.linkname = nts(buf) return next def _proc_sparse(self, tarfile): """Process a GNU sparse header plus extra headers. """ buf = self.buf 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 = nti(buf[pos:pos + 12]) numbytes = nti(buf[pos + 12:pos + 24]) 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 = nti(buf[483:495]) # If the isextended flag is given, # there are extra headers to process. while isextended == 1: buf = tarfile.fileobj.read(BLOCKSIZE) pos = 0 for i in xrange(21): try: offset = nti(buf[pos:pos + 12]) numbytes = nti(buf[pos + 12:pos + 24]) 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)) self.sparse = sp self.offset_data = tarfile.fileobj.tell() tarfile.offset = self.offset_data + self._block(self.size) self.size = origsize return self def _proc_pax(self, tarfile): """Process an extended or global header as described in POSIX.1-2001. """ # Read the header information. buf = tarfile.fileobj.read(self._block(self.size)) # A pax header stores supplemental information for either # the following file (extended) or all following files # (global). if self.type == XGLTYPE: pax_headers = tarfile.pax_headers else: pax_headers = tarfile.pax_headers.copy() # Parse pax header information. A record looks like that: # "%d %s=%s\n" % (length, keyword, value). length is the size # of the complete record including the length field itself and # the newline. keyword and value are both UTF-8 encoded strings. regex = re.compile(r"(\d+) ([^=]+)=", re.U) pos = 0 while True: match = regex.match(buf, pos) if not match: break length, keyword = match.groups() length = int(length) if length == 0: raise InvalidHeaderError("invalid header") value = buf[match.end(2) + 1:match.start(1) + length - 1] keyword = keyword.decode("utf8") value = value.decode("utf8") pax_headers[keyword] = value pos += length # Fetch the next header. try: next = self.fromtarfile(tarfile) except HeaderError: raise SubsequentHeaderError("missing or bad subsequent header") if self.type in (XHDTYPE, SOLARIS_XHDTYPE): # Patch the TarInfo object with the extended header info. next._apply_pax_info(pax_headers, tarfile.encoding, tarfile.errors) next.offset = self.offset if "size" in pax_headers: # If the extended header replaces the size field, # we need to recalculate the offset where the next # header starts. offset = next.offset_data if next.isreg() or next.type not in SUPPORTED_TYPES: offset += next._block(next.size) tarfile.offset = offset return next def _apply_pax_info(self, pax_headers, encoding, errors): """Replace fields with supplemental information from a previous pax extended or global header. """ for keyword, value in pax_headers.iteritems(): if keyword not in PAX_FIELDS: continue if keyword == "path": value = value.rstrip("/") if keyword in PAX_NUMBER_FIELDS: try: value = PAX_NUMBER_FIELDS[keyword](value) except ValueError: value = 0 else: value = uts(value, encoding, errors) setattr(self, keyword, value) self.pax_headers = pax_headers.copy() def _block(self, count): """Round up a byte count by BLOCKSIZE and return it, e.g. _block(834) => 1024. """ blocks, remainder = divmod(count, BLOCKSIZE) if remainder: blocks += 1 return blocks * BLOCKSIZE def isreg(self): return 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 = 1 # If 0, fatal errors only appear in debug # messages (if debug >= 0). If > 0, errors # are passed to the caller as exceptions. format = DEFAULT_FORMAT # The format to use when creating an archive. encoding = ENCODING # Encoding for 8-bit character strings. errors = None # Error handler for unicode conversion. tarinfo = TarInfo # The default TarInfo class to use. fileobject = ExFileObject # The default ExFileObject class to use. def __init__(self, name=None, mode="r", fileobj=None, format=None, tarinfo=None, dereference=None, ignore_zeros=None, encoding=None, errors=None, pax_headers=None, debug=None, errorlevel=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. """ modes = {"r": "rb", "a": "r+b", "w": "wb"} if mode not in modes: raise ValueError("mode must be 'r', 'a' or 'w'") self.mode = mode self._mode = modes[mode] if not fileobj: if self.mode == "a" and not os.path.exists(name): # Create nonexistent files in append mode. self.mode = "w" self._mode = "wb" fileobj = bltn_open(name, self._mode) self._extfileobj = False else: if name is None and hasattr(fileobj, "name"): name = fileobj.name if hasattr(fileobj, "mode"): self._mode = fileobj.mode self._extfileobj = True self.name = os.path.abspath(name) if name else None self.fileobj = fileobj # Init attributes. if format is not None: self.format = format if tarinfo is not None: self.tarinfo = tarinfo if dereference is not None: self.dereference = dereference if ignore_zeros is not None: self.ignore_zeros = ignore_zeros if encoding is not None: self.encoding = encoding if errors is not None: self.errors = errors elif mode == "r": self.errors = "utf-8" else: self.errors = "strict" if pax_headers is not None and self.format == PAX_FORMAT: self.pax_headers = pax_headers else: self.pax_headers = {} if debug is not None: self.debug = debug if errorlevel is not None: self.errorlevel = errorlevel # Init datastructures. self.closed = False self.members = [] # list of members as TarInfo objects self._loaded = False # flag if all members have been read self.offset = self.fileobj.tell() # current position in the archive file self.inodes = {} # dictionary caching the inodes of # archive members already added try: if self.mode == "r": self.firstmember = None self.firstmember = self.next() if self.mode == "a": # Move to the end of the archive, # before the first empty block. while True: self.fileobj.seek(self.offset) try: tarinfo = self.tarinfo.fromtarfile(self) self.members.append(tarinfo) except EOFHeaderError: self.fileobj.seek(self.offset) break except HeaderError, e: raise ReadError(str(e)) if self.mode in "aw": self._loaded = True if self.pax_headers: buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy()) self.fileobj.write(buf) self.offset += len(buf) except: if not self._extfileobj: self.fileobj.close() self.closed = True raise def _getposix(self): return self.format == USTAR_FORMAT def _setposix(self, value): import warnings warnings.warn("use the format attribute instead", DeprecationWarning, 2) if value: self.format = USTAR_FORMAT else: self.format = GNU_FORMAT posix = property(_getposix, _setposix) #-------------------------------------------------------------------------- # Below are the classmethods which act as alternate constructors to the # TarFile class. The open() method is the only one that is needed for # public use; it is the "super"-constructor and is able to select an # adequate "sub"-constructor for a particular compression using the mapping # from OPEN_METH. # # This concept allows one to subclass TarFile without losing the comfort of # the super-constructor. A sub-constructor is registered and made available # by adding it to the mapping in OPEN_METH. @classmethod def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs): """Open a tar archive for reading, writing or appending. Return an appropriate TarFile class. mode: 'r' or 'r:*' open for reading with transparent compression 'r:' open for reading exclusively uncompressed 'r:gz' open for reading with gzip compression 'r:bz2' open for reading with bzip2 compression 'a' or 'a:' open for appending, creating the file if necessary 'w' or 'w:' open for writing without compression 'w:gz' open for writing with gzip compression 'w:bz2' open for writing with bzip2 compression '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. def not_compressed(comptype): return cls.OPEN_METH[comptype] == 'taropen' for comptype in sorted(cls.OPEN_METH, key=not_compressed): func = getattr(cls, cls.OPEN_METH[comptype]) if fileobj is not None: saved_pos = fileobj.tell() try: return func(name, "r", fileobj, **kwargs) except (ReadError, CompressionError), e: if fileobj is not None: fileobj.seek(saved_pos) 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, **kwargs) elif "|" in mode: filemode, comptype = mode.split("|", 1) filemode = filemode or "r" comptype = comptype or "tar" if filemode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'") stream = _Stream(name, filemode, comptype, fileobj, bufsize) try: t = cls(name, filemode, stream, **kwargs) except: stream.close() raise t._extfileobj = False return t elif mode in ("a", "w"): return cls.taropen(name, mode, fileobj, **kwargs) raise ValueError("undiscernible mode") @classmethod def taropen(cls, name, mode="r", fileobj=None, **kwargs): """Open uncompressed tar archive name for reading or writing. """ if mode not in ("r", "a", "w"): raise ValueError("mode must be 'r', 'a' or 'w'") return cls(name, mode, fileobj, **kwargs) @classmethod def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open gzip compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'") try: import gzip gzip.GzipFile except (ImportError, AttributeError): raise CompressionError("gzip module is not available") try: fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj) except OSError: if fileobj is not None and mode == 'r': raise ReadError("not a gzip file") raise try: t = cls.taropen(name, mode, fileobj, **kwargs) except IOError: fileobj.close() if mode == 'r': raise ReadError("not a gzip file") raise except: fileobj.close() raise t._extfileobj = False return t @classmethod def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs): """Open bzip2 compressed tar archive name for reading or writing. Appending is not allowed. """ if mode not in ("r", "w"): raise ValueError("mode must be 'r' or 'w'.") try: import bz2 except ImportError: raise CompressionError("bz2 module is not available") if fileobj is not None: fileobj = _BZ2Proxy(fileobj, mode) else: fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel) try: t = cls.taropen(name, mode, fileobj, **kwargs) except (IOError, EOFError): fileobj.close() if mode == 'r': raise ReadError("not a bzip2 file") raise except: fileobj.close() raise t._extfileobj = False return t # All *open() methods are registered here. OPEN_METH = { "tar": "taropen", # uncompressed tar "gz": "gzopen", # gzip compressed tar "bz2": "bz2open" # bzip2 compressed tar } #-------------------------------------------------------------------------- # The public methods which TarFile provides: def close(self): """Close the TarFile. In write-mode, two finishing zero blocks are appended to the archive. """ if self.closed: return self.closed = True try: if self.mode in "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)) finally: if not self._extfileobj: self.fileobj.close() def getmember(self, name): """Return a TarInfo object for member `name'. If `name' can not be found in the archive, KeyError is raised. If a member occurs more than once in the archive, its last occurrence is assumed to be the most up-to-date version. """ tarinfo = self._getmember(name) if tarinfo is None: raise KeyError("filename %r not found" % name) return tarinfo def getmembers(self): """Return the members of the archive as a list of TarInfo objects. The list has the same order as the members in the archive. """ self._check() if not self._loaded: # if we want to obtain a list of self._load() # all members, we first have to # scan the whole archive. return self.members def getnames(self): """Return the members of the archive as a list of their names. It has the same order as the list returned by getmembers(). """ return [tarinfo.name for tarinfo in self.getmembers()] def gettarinfo(self, name=None, arcname=None, fileobj=None): """Create a TarInfo object from the result of os.stat or equivalent on an existing file. The file is either named by `name', or specified as a file object `fileobj' with a file descriptor. If given, `arcname' specifies an alternative name for the file in the archive, otherwise, the name is taken from the 'name' attribute of 'fileobj', or the 'name' argument. """ 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 drv, arcname = os.path.splitdrive(arcname) arcname = arcname.replace(os.sep, "/") arcname = arcname.lstrip("/") # Now, fill the TarInfo object with # information specific for the file. tarinfo = self.tarinfo() tarinfo.tarfile = self # Not needed # 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 and arcname != self.inodes[inode]: # Is it a hardlink to an already # archived file? type = LNKTYPE linkname = self.inodes[inode] else: # The inode is added only if its valid. # For win32 it is always 0. type = REGTYPE if inode[0]: self.inodes[inode] = arcname elif stat.S_ISDIR(stmd): type = DIRTYPE elif stat.S_ISFIFO(stmd): type = FIFOTYPE elif stat.S_ISLNK(stmd): type = SYMTYPE linkname = os.readlink(name) elif stat.S_ISCHR(stmd): type = CHRTYPE elif stat.S_ISBLK(stmd): type = BLKTYPE else: return None # Fill the TarInfo object with all # information we can get. tarinfo.name = arcname tarinfo.mode = stmd tarinfo.uid = statres.st_uid tarinfo.gid = statres.st_gid if type == REGTYPE: tarinfo.size = statres.st_size else: tarinfo.size = 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 tarinfo.isdir() else ""), 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, exclude=None, filter=None): """Add the file `name' to the archive. `name' may be any type of file (directory, fifo, symbolic link, etc.). If given, `arcname' specifies an alternative name for the file in the archive. Directories are added recursively by default. This can be avoided by setting `recursive' to False. `exclude' is a function that should return True for each filename to be excluded. `filter' is a function that expects a TarInfo object argument and returns the changed TarInfo object, if it returns None the TarInfo object will be excluded from the archive. """ self._check("aw") if arcname is None: arcname = name # Exclude pathnames. if exclude is not None: import warnings warnings.warn("use the filter argument instead", DeprecationWarning, 2) if exclude(name): self._dbg(2, "tarfile: Excluded %r" % name) return # Skip if somebody tries to archive the archive... if self.name is not None and os.path.abspath(name) == self.name: self._dbg(2, "tarfile: Skipped %r" % name) return self._dbg(1, name) # Create a TarInfo object from the file. tarinfo = self.gettarinfo(name, arcname) if tarinfo is None: self._dbg(1, "tarfile: Unsupported type %r" % name) return # Change or exclude the TarInfo object. if filter is not None: tarinfo = filter(tarinfo) if tarinfo is None: self._dbg(2, "tarfile: Excluded %r" % name) return # Append the tar header and data to the archive. if tarinfo.isreg(): with bltn_open(name, "rb") as f: self.addfile(tarinfo, f) elif tarinfo.isdir(): self.addfile(tarinfo) if recursive: for f in os.listdir(name): self.add(os.path.join(name, f), os.path.join(arcname, f), recursive, exclude, filter) 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 directly, or by using gettarinfo(). On Windows platforms, `fileobj' should always be opened with mode 'rb' to avoid irritation about the file size. """ self._check("aw") tarinfo = copy.copy(tarinfo) buf = tarinfo.tobuf(self.format, self.encoding, self.errors) self.fileobj.write(buf) self.offset += len(buf) # 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 directories with a safe mode. directories.append(tarinfo) tarinfo = copy.copy(tarinfo) tarinfo.mode = 0700 self.extract(tarinfo, path) # Reverse sort directories. directories.sort(key=operator.attrgetter('name')) directories.reverse() # Set correct owner, mtime and filemode on directories. for tarinfo in directories: dirpath = os.path.join(path, tarinfo.name) try: self.chown(tarinfo, dirpath) self.utime(tarinfo, dirpath) self.chmod(tarinfo, dirpath) 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, basestring): tarinfo = self.getmember(member) else: tarinfo = 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, basestring): tarinfo = self.getmember(member) else: tarinfo = 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._find_link_target(tarinfo)) else: # If there's no data associated with the member (directory, chrdev, # blkdev, etc.), return None instead of a file object. return None def _extract_member(self, tarinfo, targetpath): """Extract the TarInfo object tarinfo to a physical file called targetpath. """ # Fetch the TarInfo object for the given name # and build the destination pathname, replacing # forward slashes to platform specific separators. targetpath = targetpath.rstrip("/") targetpath = targetpath.replace("/", os.sep) # Create all upper directories. upperdirs = os.path.dirname(targetpath) if upperdirs and not os.path.exists(upperdirs): # Create directories that are not part of the archive with # default permissions. os.makedirs(upperdirs) 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: # Use a safe mode for the directory, the real mode is set # later in _extract_member(). os.mkdir(targetpath, 0700) except EnvironmentError, e: if e.errno != errno.EEXIST: raise def makefile(self, tarinfo, targetpath): """Make a file called targetpath. """ source = self.extractfile(tarinfo) try: with bltn_open(targetpath, "wb") as target: copyfileobj(source, target) finally: source.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. """ if hasattr(os, "symlink") and hasattr(os, "link"): # For systems that support symbolic and hard links. if tarinfo.issym(): if os.path.lexists(targetpath): os.unlink(targetpath) os.symlink(tarinfo.linkname, targetpath) else: # See extract(). if os.path.exists(tarinfo._link_target): if os.path.lexists(targetpath): os.unlink(targetpath) os.link(tarinfo._link_target, targetpath) else: self._extract_member(self._find_link_target(tarinfo), targetpath) else: try: self._extract_member(self._find_link_target(tarinfo), targetpath) except KeyError: raise ExtractError("unable to resolve link inside archive") 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: g = tarinfo.gid try: u = pwd.getpwnam(tarinfo.uname)[2] except KeyError: u = tarinfo.uid 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 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 # Advance the file pointer. if self.offset != self.fileobj.tell(): self.fileobj.seek(self.offset - 1) if not self.fileobj.read(1): raise ReadError("unexpected end of data") # Read the next block. tarinfo = None while True: try: tarinfo = self.tarinfo.fromtarfile(self) except EOFHeaderError, e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue except InvalidHeaderError, e: if self.ignore_zeros: self._dbg(2, "0x%X: %s" % (self.offset, e)) self.offset += BLOCKSIZE continue elif self.offset == 0: raise ReadError(str(e)) except EmptyHeaderError: if self.offset == 0: raise ReadError("empty file") except TruncatedHeaderError, e: if self.offset == 0: raise ReadError(str(e)) except SubsequentHeaderError, e: raise ReadError(str(e)) break if tarinfo is not None: self.members.append(tarinfo) else: self._loaded = True return tarinfo #-------------------------------------------------------------------------- # Little helper methods: def _getmember(self, name, tarinfo=None, normalize=False): """Find an archive member by name from bottom to top. If tarinfo is given, it is used as the starting point. """ # Ensure that all members have been loaded. members = self.getmembers() # Limit the member search list up to tarinfo. if tarinfo is not None: members = members[:members.index(tarinfo)] if normalize: name = os.path.normpath(name) for member in reversed(members): if normalize: member_name = os.path.normpath(member.name) else: member_name = member.name if name == member_name: return member 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 _find_link_target(self, tarinfo): """Find the target member of a symlink or hardlink member in the archive. """ if tarinfo.issym(): # Always search the entire archive. linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname))) limit = None else: # Search the archive before the link, because a hard link is # just a reference to an already archived file. linkname = tarinfo.linkname limit = tarinfo member = self._getmember(linkname, tarinfo=limit, normalize=True) if member is None: raise KeyError("linkname %r not found" % linkname) return member def __iter__(self): """Provide an iterator object. """ if self._loaded: return iter(self.members) else: return TarIter(self) def _dbg(self, level, msg): """Write debugging output to sys.stderr. """ if level <= self.debug: print >> sys.stderr, msg def __enter__(self): self._check() return self def __exit__(self, type, value, traceback): if type is None: self.close() else: # An exception occurred. We must not call close() because # it would try to write end-of-archive blocks and padding. if not self._extfileobj: self.fileobj.close() self.closed = True # 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 self.index == 0 and self.tarfile.firstmember is not None: tarinfo = self.tarfile.next() elif self.index < len(self.tarfile.members): tarinfo = self.tarfile.members[self.index] elif not self.tarfile._loaded: tarinfo = self.tarfile.next() if not tarinfo: self.tarfile._loaded = True raise StopIteration else: 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): from warnings import warnpy3k warnpy3k("the TarFileCompat class has been removed in Python 3.0", stacklevel=2) 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 tinfo = TarInfo(zinfo.filename) tinfo.size = len(bytes) tinfo.mtime = calendar.timegm(zinfo.date_time) self.tarfile.addfile(tinfo, 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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