【python之旅】python的模块

  1 class ZipFile(object):
  2     """ Class with methods to open, read, write, close, list zip files.
  3 
  4     z = ZipFile(file, mode="r", compression=ZIP_STORED, allowZip64=False)
  5 
  6     file: Either the path to the file, or a file-like object.
  7           If it is a path, the file will be opened and closed by ZipFile.
  8     mode: The mode can be either read "r", write "w" or append "a".
  9     compression: ZIP_STORED (no compression) or ZIP_DEFLATED (requires zlib).
 10     allowZip64: if True ZipFile will create files with ZIP64 extensions when
 11                 needed, otherwise it will raise an exception when this would
 12                 be necessary.
 13 
 14     """
 15 
 16     fp = None                   # Set here since __del__ checks it
 17 
 18     def __init__(self, file, mode="r", compression=ZIP_STORED, allowZip64=False):
 19         """Open the ZIP file with mode read "r", write "w" or append "a"."""
 20         if mode not in ("r", "w", "a"):
 21             raise RuntimeError(‘ZipFile() requires mode "r", "w", or "a"‘)
 22 
 23         if compression == ZIP_STORED:
 24             pass
 25         elif compression == ZIP_DEFLATED:
 26             if not zlib:
 27                 raise RuntimeError, 28                       "Compression requires the (missing) zlib module"
 29         else:
 30             raise RuntimeError, "That compression method is not supported"
 31 
 32         self._allowZip64 = allowZip64
 33         self._didModify = False
 34         self.debug = 0  # Level of printing: 0 through 3
 35         self.NameToInfo = {}    # Find file info given name
 36         self.filelist = []      # List of ZipInfo instances for archive
 37         self.compression = compression  # Method of compression
 38         self.mode = key = mode.replace(‘b‘, ‘‘)[0]
 39         self.pwd = None
 40         self._comment = ‘‘
 41 
 42         # Check if we were passed a file-like object
 43         if isinstance(file, basestring):
 44             self._filePassed = 0
 45             self.filename = file
 46             modeDict = {‘r‘ : ‘rb‘, ‘w‘: ‘wb‘, ‘a‘ : ‘r+b‘}
 47             try:
 48                 self.fp = open(file, modeDict[mode])
 49             except IOError:
 50                 if mode == ‘a‘:
 51                     mode = key = ‘w‘
 52                     self.fp = open(file, modeDict[mode])
 53                 else:
 54                     raise
 55         else:
 56             self._filePassed = 1
 57             self.fp = file
 58             self.filename = getattr(file, ‘name‘, None)
 59 
 60         try:
 61             if key == ‘r‘:
 62                 self._RealGetContents()
 63             elif key == ‘w‘:
 64                 # set the modified flag so central directory gets written
 65                 # even if no files are added to the archive
 66                 self._didModify = True
 67             elif key == ‘a‘:
 68                 try:
 69                     # See if file is a zip file
 70                     self._RealGetContents()
 71                     # seek to start of directory and overwrite
 72                     self.fp.seek(self.start_dir, 0)
 73                 except BadZipfile:
 74                     # file is not a zip file, just append
 75                     self.fp.seek(0, 2)
 76 
 77                     # set the modified flag so central directory gets written
 78                     # even if no files are added to the archive
 79                     self._didModify = True
 80             else:
 81                 raise RuntimeError(‘Mode must be "r", "w" or "a"‘)
 82         except:
 83             fp = self.fp
 84             self.fp = None
 85             if not self._filePassed:
 86                 fp.close()
 87             raise
 88 
 89     def __enter__(self):
 90         return self
 91 
 92     def __exit__(self, type, value, traceback):
 93         self.close()
 94 
 95     def _RealGetContents(self):
 96         """Read in the table of contents for the ZIP file."""
 97         fp = self.fp
 98         try:
 99             endrec = _EndRecData(fp)
100         except IOError:
101             raise BadZipfile("File is not a zip file")
102         if not endrec:
103             raise BadZipfile, "File is not a zip file"
104         if self.debug > 1:
105             print endrec
106         size_cd = endrec[_ECD_SIZE]             # bytes in central directory
107         offset_cd = endrec[_ECD_OFFSET]         # offset of central directory
108         self._comment = endrec[_ECD_COMMENT]    # archive comment
109 
110         # "concat" is zero, unless zip was concatenated to another file
111         concat = endrec[_ECD_LOCATION] - size_cd - offset_cd
112         if endrec[_ECD_SIGNATURE] == stringEndArchive64:
113             # If Zip64 extension structures are present, account for them
114             concat -= (sizeEndCentDir64 + sizeEndCentDir64Locator)
115 
116         if self.debug > 2:
117             inferred = concat + offset_cd
118             print "given, inferred, offset", offset_cd, inferred, concat
119         # self.start_dir:  Position of start of central directory
120         self.start_dir = offset_cd + concat
121         fp.seek(self.start_dir, 0)
122         data = fp.read(size_cd)
123         fp = cStringIO.StringIO(data)
124         total = 0
125         while total < size_cd:
126             centdir = fp.read(sizeCentralDir)
127             if len(centdir) != sizeCentralDir:
128                 raise BadZipfile("Truncated central directory")
129             centdir = struct.unpack(structCentralDir, centdir)
130             if centdir[_CD_SIGNATURE] != stringCentralDir:
131                 raise BadZipfile("Bad magic number for central directory")
132             if self.debug > 2:
133                 print centdir
134             filename = fp.read(centdir[_CD_FILENAME_LENGTH])
135             # Create ZipInfo instance to store file information
136             x = ZipInfo(filename)
137             x.extra = fp.read(centdir[_CD_EXTRA_FIELD_LENGTH])
138             x.comment = fp.read(centdir[_CD_COMMENT_LENGTH])
139             x.header_offset = centdir[_CD_LOCAL_HEADER_OFFSET]
140             (x.create_version, x.create_system, x.extract_version, x.reserved,
141                 x.flag_bits, x.compress_type, t, d,
142                 x.CRC, x.compress_size, x.file_size) = centdir[1:12]
143             x.volume, x.internal_attr, x.external_attr = centdir[15:18]
144             # Convert date/time code to (year, month, day, hour, min, sec)
145             x._raw_time = t
146             x.date_time = ( (d>>9)+1980, (d>>5)&0xF, d&0x1F,
147                                      t>>11, (t>>5)&0x3F, (t&0x1F) * 2 )
148 
149             x._decodeExtra()
150             x.header_offset = x.header_offset + concat
151             x.filename = x._decodeFilename()
152             self.filelist.append(x)
153             self.NameToInfo[x.filename] = x
154 
155             # update total bytes read from central directory
156             total = (total + sizeCentralDir + centdir[_CD_FILENAME_LENGTH]
157                      + centdir[_CD_EXTRA_FIELD_LENGTH]
158                      + centdir[_CD_COMMENT_LENGTH])
159 
160             if self.debug > 2:
161                 print "total", total
162 
163 
164     def namelist(self):
165         """Return a list of file names in the archive."""
166         l = []
167         for data in self.filelist:
168             l.append(data.filename)
169         return l
170 
171     def infolist(self):
172         """Return a list of class ZipInfo instances for files in the
173         archive."""
174         return self.filelist
175 
176     def printdir(self):
177         """Print a table of contents for the zip file."""
178         print "%-46s %19s %12s" % ("File Name", "Modified    ", "Size")
179         for zinfo in self.filelist:
180             date = "%d-%02d-%02d %02d:%02d:%02d" % zinfo.date_time[:6]
181             print "%-46s %s %12d" % (zinfo.filename, date, zinfo.file_size)
182 
183     def testzip(self):
184         """Read all the files and check the CRC."""
185         chunk_size = 2 ** 20
186         for zinfo in self.filelist:
187             try:
188                 # Read by chunks, to avoid an OverflowError or a
189                 # MemoryError with very large embedded files.
190                 with self.open(zinfo.filename, "r") as f:
191                     while f.read(chunk_size):     # Check CRC-32
192                         pass
193             except BadZipfile:
194                 return zinfo.filename
195 
196     def getinfo(self, name):
197         """Return the instance of ZipInfo given ‘name‘."""
198         info = self.NameToInfo.get(name)
199         if info is None:
200             raise KeyError(
201                 ‘There is no item named %r in the archive‘ % name)
202 
203         return info
204 
205     def setpassword(self, pwd):
206         """Set default password for encrypted files."""
207         self.pwd = pwd
208 
209     @property
210     def comment(self):
211         """The comment text associated with the ZIP file."""
212         return self._comment
213 
214     @comment.setter
215     def comment(self, comment):
216         # check for valid comment length
217         if len(comment) > ZIP_MAX_COMMENT:
218             import warnings
219             warnings.warn(‘Archive comment is too long; truncating to %d bytes‘
220                           % ZIP_MAX_COMMENT, stacklevel=2)
221             comment = comment[:ZIP_MAX_COMMENT]
222         self._comment = comment
223         self._didModify = True
224 
225     def read(self, name, pwd=None):
226         """Return file bytes (as a string) for name."""
227         return self.open(name, "r", pwd).read()
228 
229     def open(self, name, mode="r", pwd=None):
230         """Return file-like object for ‘name‘."""
231         if mode not in ("r", "U", "rU"):
232             raise RuntimeError, ‘open() requires mode "r", "U", or "rU"‘
233         if not self.fp:
234             raise RuntimeError, 235                   "Attempt to read ZIP archive that was already closed"
236 
237         # Only open a new file for instances where we were not
238         # given a file object in the constructor
239         if self._filePassed:
240             zef_file = self.fp
241             should_close = False
242         else:
243             zef_file = open(self.filename, ‘rb‘)
244             should_close = True
245 
246         try:
247             # Make sure we have an info object
248             if isinstance(name, ZipInfo):
249                 # ‘name‘ is already an info object
250                 zinfo = name
251             else:
252                 # Get info object for name
253                 zinfo = self.getinfo(name)
254 
255             zef_file.seek(zinfo.header_offset, 0)
256 
257             # Skip the file header:
258             fheader = zef_file.read(sizeFileHeader)
259             if len(fheader) != sizeFileHeader:
260                 raise BadZipfile("Truncated file header")
261             fheader = struct.unpack(structFileHeader, fheader)
262             if fheader[_FH_SIGNATURE] != stringFileHeader:
263                 raise BadZipfile("Bad magic number for file header")
264 
265             fname = zef_file.read(fheader[_FH_FILENAME_LENGTH])
266             if fheader[_FH_EXTRA_FIELD_LENGTH]:
267                 zef_file.read(fheader[_FH_EXTRA_FIELD_LENGTH])
268 
269             if fname != zinfo.orig_filename:
270                 raise BadZipfile, 271                         ‘File name in directory "%s" and header "%s" differ.‘ % (
272                             zinfo.orig_filename, fname)
273 
274             # check for encrypted flag & handle password
275             is_encrypted = zinfo.flag_bits & 0x1
276             zd = None
277             if is_encrypted:
278                 if not pwd:
279                     pwd = self.pwd
280                 if not pwd:
281                     raise RuntimeError, "File %s is encrypted, " 282                         "password required for extraction" % name
283 
284                 zd = _ZipDecrypter(pwd)
285                 # The first 12 bytes in the cypher stream is an encryption header
286                 #  used to strengthen the algorithm. The first 11 bytes are
287                 #  completely random, while the 12th contains the MSB of the CRC,
288                 #  or the MSB of the file time depending on the header type
289                 #  and is used to check the correctness of the password.
290                 bytes = zef_file.read(12)
291                 h = map(zd, bytes[0:12])
292                 if zinfo.flag_bits & 0x8:
293                     # compare against the file type from extended local headers
294                     check_byte = (zinfo._raw_time >> 8) & 0xff
295                 else:
296                     # compare against the CRC otherwise
297                     check_byte = (zinfo.CRC >> 24) & 0xff
298                 if ord(h[11]) != check_byte:
299                     raise RuntimeError("Bad password for file", name)
300 
301             return ZipExtFile(zef_file, mode, zinfo, zd,
302                     close_fileobj=should_close)
303         except:
304             if should_close:
305                 zef_file.close()
306             raise
307 
308     def extract(self, member, path=None, pwd=None):
309         """Extract a member from the archive to the current working directory,
310            using its full name. Its file information is extracted as accurately
311            as possible. `member‘ may be a filename or a ZipInfo object. You can
312            specify a different directory using `path‘.
313         """
314         if not isinstance(member, ZipInfo):
315             member = self.getinfo(member)
316 
317         if path is None:
318             path = os.getcwd()
319 
320         return self._extract_member(member, path, pwd)
321 
322     def extractall(self, path=None, members=None, pwd=None):
323         """Extract all members from the archive to the current working
324            directory. `path‘ specifies a different directory to extract to.
325            `members‘ is optional and must be a subset of the list returned
326            by namelist().
327         """
328         if members is None:
329             members = self.namelist()
330 
331         for zipinfo in members:
332             self.extract(zipinfo, path, pwd)
333 
334     def _extract_member(self, member, targetpath, pwd):
335         """Extract the ZipInfo object ‘member‘ to a physical
336            file on the path targetpath.
337         """
338         # build the destination pathname, replacing
339         # forward slashes to platform specific separators.
340         arcname = member.filename.replace(‘/‘, os.path.sep)
341 
342         if os.path.altsep:
343             arcname = arcname.replace(os.path.altsep, os.path.sep)
344         # interpret absolute pathname as relative, remove drive letter or
345         # UNC path, redundant separators, "." and ".." components.
346         arcname = os.path.splitdrive(arcname)[1]
347         arcname = os.path.sep.join(x for x in arcname.split(os.path.sep)
348                     if x not in (‘‘, os.path.curdir, os.path.pardir))
349         if os.path.sep == ‘\\‘:
350             # filter illegal characters on Windows
351             illegal = ‘:<>|"?*‘
352             if isinstance(arcname, unicode):
353                 table = {ord(c): ord(‘_‘) for c in illegal}
354             else:
355                 table = string.maketrans(illegal, ‘_‘ * len(illegal))
356             arcname = arcname.translate(table)
357             # remove trailing dots
358             arcname = (x.rstrip(‘.‘) for x in arcname.split(os.path.sep))
359             arcname = os.path.sep.join(x for x in arcname if x)
360 
361         targetpath = os.path.join(targetpath, arcname)
362         targetpath = os.path.normpath(targetpath)
363 
364         # Create all upper directories if necessary.
365         upperdirs = os.path.dirname(targetpath)
366         if upperdirs and not os.path.exists(upperdirs):
367             os.makedirs(upperdirs)
368 
369         if member.filename[-1] == ‘/‘:
370             if not os.path.isdir(targetpath):
371                 os.mkdir(targetpath)
372             return targetpath
373 
374         with self.open(member, pwd=pwd) as source, 375              file(targetpath, "wb") as target:
376             shutil.copyfileobj(source, target)
377 
378         return targetpath
379 
380     def _writecheck(self, zinfo):
381         """Check for errors before writing a file to the archive."""
382         if zinfo.filename in self.NameToInfo:
383             import warnings
384             warnings.warn(‘Duplicate name: %r‘ % zinfo.filename, stacklevel=3)
385         if self.mode not in ("w", "a"):
386             raise RuntimeError, ‘write() requires mode "w" or "a"‘
387         if not self.fp:
388             raise RuntimeError, 389                   "Attempt to write ZIP archive that was already closed"
390         if zinfo.compress_type == ZIP_DEFLATED and not zlib:
391             raise RuntimeError, 392                   "Compression requires the (missing) zlib module"
393         if zinfo.compress_type not in (ZIP_STORED, ZIP_DEFLATED):
394             raise RuntimeError, 395                   "That compression method is not supported"
396         if not self._allowZip64:
397             requires_zip64 = None
398             if len(self.filelist) >= ZIP_FILECOUNT_LIMIT:
399                 requires_zip64 = "Files count"
400             elif zinfo.file_size > ZIP64_LIMIT:
401                 requires_zip64 = "Filesize"
402             elif zinfo.header_offset > ZIP64_LIMIT:
403                 requires_zip64 = "Zipfile size"
404             if requires_zip64:
405                 raise LargeZipFile(requires_zip64 +
406                                    " would require ZIP64 extensions")
407 
408     def write(self, filename, arcname=None, compress_type=None):
409         """Put the bytes from filename into the archive under the name
410         arcname."""
411         if not self.fp:
412             raise RuntimeError(
413                   "Attempt to write to ZIP archive that was already closed")
414 
415         st = os.stat(filename)
416         isdir = stat.S_ISDIR(st.st_mode)
417         mtime = time.localtime(st.st_mtime)
418         date_time = mtime[0:6]
419         # Create ZipInfo instance to store file information
420         if arcname is None:
421             arcname = filename
422         arcname = os.path.normpath(os.path.splitdrive(arcname)[1])
423         while arcname[0] in (os.sep, os.altsep):
424             arcname = arcname[1:]
425         if isdir:
426             arcname += ‘/‘
427         zinfo = ZipInfo(arcname, date_time)
428         zinfo.external_attr = (st[0] & 0xFFFF) << 16L      # Unix attributes
429         if compress_type is None:
430             zinfo.compress_type = self.compression
431         else:
432             zinfo.compress_type = compress_type
433 
434         zinfo.file_size = st.st_size
435         zinfo.flag_bits = 0x00
436         zinfo.header_offset = self.fp.tell()    # Start of header bytes
437 
438         self._writecheck(zinfo)
439         self._didModify = True
440 
441         if isdir:
442             zinfo.file_size = 0
443             zinfo.compress_size = 0
444             zinfo.CRC = 0
445             zinfo.external_attr |= 0x10  # MS-DOS directory flag
446             self.filelist.append(zinfo)
447             self.NameToInfo[zinfo.filename] = zinfo
448             self.fp.write(zinfo.FileHeader(False))
449             return
450 
451         with open(filename, "rb") as fp:
452             # Must overwrite CRC and sizes with correct data later
453             zinfo.CRC = CRC = 0
454             zinfo.compress_size = compress_size = 0
455             # Compressed size can be larger than uncompressed size
456             zip64 = self._allowZip64 and 457                     zinfo.file_size * 1.05 > ZIP64_LIMIT
458             self.fp.write(zinfo.FileHeader(zip64))
459             if zinfo.compress_type == ZIP_DEFLATED:
460                 cmpr = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
461                      zlib.DEFLATED, -15)
462             else:
463                 cmpr = None
464             file_size = 0
465             while 1:
466                 buf = fp.read(1024 * 8)
467                 if not buf:
468                     break
469                 file_size = file_size + len(buf)
470                 CRC = crc32(buf, CRC) & 0xffffffff
471                 if cmpr:
472                     buf = cmpr.compress(buf)
473                     compress_size = compress_size + len(buf)
474                 self.fp.write(buf)
475         if cmpr:
476             buf = cmpr.flush()
477             compress_size = compress_size + len(buf)
478             self.fp.write(buf)
479             zinfo.compress_size = compress_size
480         else:
481             zinfo.compress_size = file_size
482         zinfo.CRC = CRC
483         zinfo.file_size = file_size
484         if not zip64 and self._allowZip64:
485             if file_size > ZIP64_LIMIT:
486                 raise RuntimeError(‘File size has increased during compressing‘)
487             if compress_size > ZIP64_LIMIT:
488                 raise RuntimeError(‘Compressed size larger than uncompressed size‘)
489         # Seek backwards and write file header (which will now include
490         # correct CRC and file sizes)
491         position = self.fp.tell()       # Preserve current position in file
492         self.fp.seek(zinfo.header_offset, 0)
493         self.fp.write(zinfo.FileHeader(zip64))
494         self.fp.seek(position, 0)
495         self.filelist.append(zinfo)
496         self.NameToInfo[zinfo.filename] = zinfo
497 
498     def writestr(self, zinfo_or_arcname, bytes, compress_type=None):
499         """Write a file into the archive.  The contents is the string
500         ‘bytes‘.  ‘zinfo_or_arcname‘ is either a ZipInfo instance or
501         the name of the file in the archive."""
502         if not isinstance(zinfo_or_arcname, ZipInfo):
503             zinfo = ZipInfo(filename=zinfo_or_arcname,
504                             date_time=time.localtime(time.time())[:6])
505 
506             zinfo.compress_type = self.compression
507             if zinfo.filename[-1] == ‘/‘:
508                 zinfo.external_attr = 0o40775 << 16   # drwxrwxr-x
509                 zinfo.external_attr |= 0x10           # MS-DOS directory flag
510             else:
511                 zinfo.external_attr = 0o600 << 16     # ?rw-------
512         else:
513             zinfo = zinfo_or_arcname
514 
515         if not self.fp:
516             raise RuntimeError(
517                   "Attempt to write to ZIP archive that was already closed")
518 
519         if compress_type is not None:
520             zinfo.compress_type = compress_type
521 
522         zinfo.file_size = len(bytes)            # Uncompressed size
523         zinfo.header_offset = self.fp.tell()    # Start of header bytes
524         self._writecheck(zinfo)
525         self._didModify = True
526         zinfo.CRC = crc32(bytes) & 0xffffffff       # CRC-32 checksum
527         if zinfo.compress_type == ZIP_DEFLATED:
528             co = zlib.compressobj(zlib.Z_DEFAULT_COMPRESSION,
529                  zlib.DEFLATED, -15)
530             bytes = co.compress(bytes) + co.flush()
531             zinfo.compress_size = len(bytes)    # Compressed size
532         else:
533             zinfo.compress_size = zinfo.file_size
534         zip64 = zinfo.file_size > ZIP64_LIMIT or 535                 zinfo.compress_size > ZIP64_LIMIT
536         if zip64 and not self._allowZip64:
537             raise LargeZipFile("Filesize would require ZIP64 extensions")
538         self.fp.write(zinfo.FileHeader(zip64))
539         self.fp.write(bytes)
540         if zinfo.flag_bits & 0x08:
541             # Write CRC and file sizes after the file data
542             fmt = ‘<LQQ‘ if zip64 else ‘<LLL‘
543             self.fp.write(struct.pack(fmt, zinfo.CRC, zinfo.compress_size,
544                   zinfo.file_size))
545         self.fp.flush()
546         self.filelist.append(zinfo)
547         self.NameToInfo[zinfo.filename] = zinfo
548 
549     def __del__(self):
550         """Call the "close()" method in case the user forgot."""
551         self.close()
552 
553     def close(self):
554         """Close the file, and for mode "w" and "a" write the ending
555         records."""
556         if self.fp is None:
557             return
558 
559         try:
560             if self.mode in ("w", "a") and self._didModify: # write ending records
561                 pos1 = self.fp.tell()
562                 for zinfo in self.filelist:         # write central directory
563                     dt = zinfo.date_time
564                     dosdate = (dt[0] - 1980) << 9 | dt[1] << 5 | dt[2]
565                     dostime = dt[3] << 11 | dt[4] << 5 | (dt[5] // 2)
566                     extra = []
567                     if zinfo.file_size > ZIP64_LIMIT 568                             or zinfo.compress_size > ZIP64_LIMIT:
569                         extra.append(zinfo.file_size)
570                         extra.append(zinfo.compress_size)
571                         file_size = 0xffffffff
572                         compress_size = 0xffffffff
573                     else:
574                         file_size = zinfo.file_size
575                         compress_size = zinfo.compress_size
576 
577                     if zinfo.header_offset > ZIP64_LIMIT:
578                         extra.append(zinfo.header_offset)
579                         header_offset = 0xffffffffL
580                     else:
581                         header_offset = zinfo.header_offset
582 
583                     extra_data = zinfo.extra
584                     if extra:
585                         # Append a ZIP64 field to the extra‘s
586                         extra_data = struct.pack(
587                                 ‘<HH‘ + ‘Q‘*len(extra),
588                                 1, 8*len(extra), *extra) + extra_data
589 
590                         extract_version = max(45, zinfo.extract_version)
591                         create_version = max(45, zinfo.create_version)
592                     else:
593                         extract_version = zinfo.extract_version
594                         create_version = zinfo.create_version
595 
596                     try:
597                         filename, flag_bits = zinfo._encodeFilenameFlags()
598                         centdir = struct.pack(structCentralDir,
599                         stringCentralDir, create_version,
600                         zinfo.create_system, extract_version, zinfo.reserved,
601                         flag_bits, zinfo.compress_type, dostime, dosdate,
602                         zinfo.CRC, compress_size, file_size,
603                         len(filename), len(extra_data), len(zinfo.comment),
604                         0, zinfo.internal_attr, zinfo.external_attr,
605                         header_offset)
606                     except DeprecationWarning:
607                         print >>sys.stderr, (structCentralDir,
608                         stringCentralDir, create_version,
609                         zinfo.create_system, extract_version, zinfo.reserved,
610                         zinfo.flag_bits, zinfo.compress_type, dostime, dosdate,
611                         zinfo.CRC, compress_size, file_size,
612                         len(zinfo.filename), len(extra_data), len(zinfo.comment),
613                         0, zinfo.internal_attr, zinfo.external_attr,
614                         header_offset)
615                         raise
616                     self.fp.write(centdir)
617                     self.fp.write(filename)
618                     self.fp.write(extra_data)
619                     self.fp.write(zinfo.comment)
620 
621                 pos2 = self.fp.tell()
622                 # Write end-of-zip-archive record
623                 centDirCount = len(self.filelist)
624                 centDirSize = pos2 - pos1
625                 centDirOffset = pos1
626                 requires_zip64 = None
627                 if centDirCount > ZIP_FILECOUNT_LIMIT:
628                     requires_zip64 = "Files count"
629                 elif centDirOffset > ZIP64_LIMIT:
630                     requires_zip64 = "Central directory offset"
631                 elif centDirSize > ZIP64_LIMIT:
632                     requires_zip64 = "Central directory size"
633                 if requires_zip64:
634                     # Need to write the ZIP64 end-of-archive records
635                     if not self._allowZip64:
636                         raise LargeZipFile(requires_zip64 +
637                                            " would require ZIP64 extensions")
638                     zip64endrec = struct.pack(
639                             structEndArchive64, stringEndArchive64,
640                             44, 45, 45, 0, 0, centDirCount, centDirCount,
641                             centDirSize, centDirOffset)
642                     self.fp.write(zip64endrec)
643 
644                     zip64locrec = struct.pack(
645                             structEndArchive64Locator,
646                             stringEndArchive64Locator, 0, pos2, 1)
647                     self.fp.write(zip64locrec)
648                     centDirCount = min(centDirCount, 0xFFFF)
649                     centDirSize = min(centDirSize, 0xFFFFFFFF)
650                     centDirOffset = min(centDirOffset, 0xFFFFFFFF)
651 
652                 endrec = struct.pack(structEndArchive, stringEndArchive,
653                                     0, 0, centDirCount, centDirCount,
654                                     centDirSize, centDirOffset, len(self._comment))
655                 self.fp.write(endrec)
656                 self.fp.write(self._comment)
657                 self.fp.flush()
658         finally:
659             fp = self.fp
660             self.fp = None
661             if not self._filePassed:
662                 fp.close()

  1 class TarFile(object):
  2     """The TarFile Class provides an interface to tar archives.
  3     """
  4 
  5     debug = 0                   # May be set from 0 (no msgs) to 3 (all msgs)
  6 
  7     dereference = False         # If true, add content of linked file to the
  8                                 # tar file, else the link.
  9 
 10     ignore_zeros = False        # If true, skips empty or invalid blocks and
 11                                 # continues processing.
 12 
 13     errorlevel = 1              # If 0, fatal errors only appear in debug
 14                                 # messages (if debug >= 0). If > 0, errors
 15                                 # are passed to the caller as exceptions.
 16 
 17     format = DEFAULT_FORMAT     # The format to use when creating an archive.
 18 
 19     encoding = ENCODING         # Encoding for 8-bit character strings.
 20 
 21     errors = None               # Error handler for unicode conversion.
 22 
 23     tarinfo = TarInfo           # The default TarInfo class to use.
 24 
 25     fileobject = ExFileObject   # The default ExFileObject class to use.
 26 
 27     def __init__(self, name=None, mode="r", fileobj=None, format=None,
 28             tarinfo=None, dereference=None, ignore_zeros=None, encoding=None,
 29             errors=None, pax_headers=None, debug=None, errorlevel=None):
 30         """Open an (uncompressed) tar archive `name‘. `mode‘ is either ‘r‘ to
 31            read from an existing archive, ‘a‘ to append data to an existing
 32            file or ‘w‘ to create a new file overwriting an existing one. `mode‘
 33            defaults to ‘r‘.
 34            If `fileobj‘ is given, it is used for reading or writing data. If it
 35            can be determined, `mode‘ is overridden by `fileobj‘s mode.
 36            `fileobj‘ is not closed, when TarFile is closed.
 37         """
 38         modes = {"r": "rb", "a": "r+b", "w": "wb"}
 39         if mode not in modes:
 40             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
 41         self.mode = mode
 42         self._mode = modes[mode]
 43 
 44         if not fileobj:
 45             if self.mode == "a" and not os.path.exists(name):
 46                 # Create nonexistent files in append mode.
 47                 self.mode = "w"
 48                 self._mode = "wb"
 49             fileobj = bltn_open(name, self._mode)
 50             self._extfileobj = False
 51         else:
 52             if name is None and hasattr(fileobj, "name"):
 53                 name = fileobj.name
 54             if hasattr(fileobj, "mode"):
 55                 self._mode = fileobj.mode
 56             self._extfileobj = True
 57         self.name = os.path.abspath(name) if name else None
 58         self.fileobj = fileobj
 59 
 60         # Init attributes.
 61         if format is not None:
 62             self.format = format
 63         if tarinfo is not None:
 64             self.tarinfo = tarinfo
 65         if dereference is not None:
 66             self.dereference = dereference
 67         if ignore_zeros is not None:
 68             self.ignore_zeros = ignore_zeros
 69         if encoding is not None:
 70             self.encoding = encoding
 71 
 72         if errors is not None:
 73             self.errors = errors
 74         elif mode == "r":
 75             self.errors = "utf-8"
 76         else:
 77             self.errors = "strict"
 78 
 79         if pax_headers is not None and self.format == PAX_FORMAT:
 80             self.pax_headers = pax_headers
 81         else:
 82             self.pax_headers = {}
 83 
 84         if debug is not None:
 85             self.debug = debug
 86         if errorlevel is not None:
 87             self.errorlevel = errorlevel
 88 
 89         # Init datastructures.
 90         self.closed = False
 91         self.members = []       # list of members as TarInfo objects
 92         self._loaded = False    # flag if all members have been read
 93         self.offset = self.fileobj.tell()
 94                                 # current position in the archive file
 95         self.inodes = {}        # dictionary caching the inodes of
 96                                 # archive members already added
 97 
 98         try:
 99             if self.mode == "r":
100                 self.firstmember = None
101                 self.firstmember = self.next()
102 
103             if self.mode == "a":
104                 # Move to the end of the archive,
105                 # before the first empty block.
106                 while True:
107                     self.fileobj.seek(self.offset)
108                     try:
109                         tarinfo = self.tarinfo.fromtarfile(self)
110                         self.members.append(tarinfo)
111                     except EOFHeaderError:
112                         self.fileobj.seek(self.offset)
113                         break
114                     except HeaderError, e:
115                         raise ReadError(str(e))
116 
117             if self.mode in "aw":
118                 self._loaded = True
119 
120                 if self.pax_headers:
121                     buf = self.tarinfo.create_pax_global_header(self.pax_headers.copy())
122                     self.fileobj.write(buf)
123                     self.offset += len(buf)
124         except:
125             if not self._extfileobj:
126                 self.fileobj.close()
127             self.closed = True
128             raise
129 
130     def _getposix(self):
131         return self.format == USTAR_FORMAT
132     def _setposix(self, value):
133         import warnings
134         warnings.warn("use the format attribute instead", DeprecationWarning,
135                       2)
136         if value:
137             self.format = USTAR_FORMAT
138         else:
139             self.format = GNU_FORMAT
140     posix = property(_getposix, _setposix)
141 
142     #--------------------------------------------------------------------------
143     # Below are the classmethods which act as alternate constructors to the
144     # TarFile class. The open() method is the only one that is needed for
145     # public use; it is the "super"-constructor and is able to select an
146     # adequate "sub"-constructor for a particular compression using the mapping
147     # from OPEN_METH.
148     #
149     # This concept allows one to subclass TarFile without losing the comfort of
150     # the super-constructor. A sub-constructor is registered and made available
151     # by adding it to the mapping in OPEN_METH.
152 
153     @classmethod
154     def open(cls, name=None, mode="r", fileobj=None, bufsize=RECORDSIZE, **kwargs):
155         """Open a tar archive for reading, writing or appending. Return
156            an appropriate TarFile class.
157 
158            mode:
159            ‘r‘ or ‘r:*‘ open for reading with transparent compression
160            ‘r:‘         open for reading exclusively uncompressed
161            ‘r:gz‘       open for reading with gzip compression
162            ‘r:bz2‘      open for reading with bzip2 compression
163            ‘a‘ or ‘a:‘  open for appending, creating the file if necessary
164            ‘w‘ or ‘w:‘  open for writing without compression
165            ‘w:gz‘       open for writing with gzip compression
166            ‘w:bz2‘      open for writing with bzip2 compression
167 
168            ‘r|*‘        open a stream of tar blocks with transparent compression
169            ‘r|‘         open an uncompressed stream of tar blocks for reading
170            ‘r|gz‘       open a gzip compressed stream of tar blocks
171            ‘r|bz2‘      open a bzip2 compressed stream of tar blocks
172            ‘w|‘         open an uncompressed stream for writing
173            ‘w|gz‘       open a gzip compressed stream for writing
174            ‘w|bz2‘      open a bzip2 compressed stream for writing
175         """
176 
177         if not name and not fileobj:
178             raise ValueError("nothing to open")
179 
180         if mode in ("r", "r:*"):
181             # Find out which *open() is appropriate for opening the file.
182             for comptype in cls.OPEN_METH:
183                 func = getattr(cls, cls.OPEN_METH[comptype])
184                 if fileobj is not None:
185                     saved_pos = fileobj.tell()
186                 try:
187                     return func(name, "r", fileobj, **kwargs)
188                 except (ReadError, CompressionError), e:
189                     if fileobj is not None:
190                         fileobj.seek(saved_pos)
191                     continue
192             raise ReadError("file could not be opened successfully")
193 
194         elif ":" in mode:
195             filemode, comptype = mode.split(":", 1)
196             filemode = filemode or "r"
197             comptype = comptype or "tar"
198 
199             # Select the *open() function according to
200             # given compression.
201             if comptype in cls.OPEN_METH:
202                 func = getattr(cls, cls.OPEN_METH[comptype])
203             else:
204                 raise CompressionError("unknown compression type %r" % comptype)
205             return func(name, filemode, fileobj, **kwargs)
206 
207         elif "|" in mode:
208             filemode, comptype = mode.split("|", 1)
209             filemode = filemode or "r"
210             comptype = comptype or "tar"
211 
212             if filemode not in ("r", "w"):
213                 raise ValueError("mode must be ‘r‘ or ‘w‘")
214 
215             stream = _Stream(name, filemode, comptype, fileobj, bufsize)
216             try:
217                 t = cls(name, filemode, stream, **kwargs)
218             except:
219                 stream.close()
220                 raise
221             t._extfileobj = False
222             return t
223 
224         elif mode in ("a", "w"):
225             return cls.taropen(name, mode, fileobj, **kwargs)
226 
227         raise ValueError("undiscernible mode")
228 
229     @classmethod
230     def taropen(cls, name, mode="r", fileobj=None, **kwargs):
231         """Open uncompressed tar archive name for reading or writing.
232         """
233         if mode not in ("r", "a", "w"):
234             raise ValueError("mode must be ‘r‘, ‘a‘ or ‘w‘")
235         return cls(name, mode, fileobj, **kwargs)
236 
237     @classmethod
238     def gzopen(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
239         """Open gzip compressed tar archive name for reading or writing.
240            Appending is not allowed.
241         """
242         if mode not in ("r", "w"):
243             raise ValueError("mode must be ‘r‘ or ‘w‘")
244 
245         try:
246             import gzip
247             gzip.GzipFile
248         except (ImportError, AttributeError):
249             raise CompressionError("gzip module is not available")
250 
251         try:
252             fileobj = gzip.GzipFile(name, mode, compresslevel, fileobj)
253         except OSError:
254             if fileobj is not None and mode == ‘r‘:
255                 raise ReadError("not a gzip file")
256             raise
257 
258         try:
259             t = cls.taropen(name, mode, fileobj, **kwargs)
260         except IOError:
261             fileobj.close()
262             if mode == ‘r‘:
263                 raise ReadError("not a gzip file")
264             raise
265         except:
266             fileobj.close()
267             raise
268         t._extfileobj = False
269         return t
270 
271     @classmethod
272     def bz2open(cls, name, mode="r", fileobj=None, compresslevel=9, **kwargs):
273         """Open bzip2 compressed tar archive name for reading or writing.
274            Appending is not allowed.
275         """
276         if mode not in ("r", "w"):
277             raise ValueError("mode must be ‘r‘ or ‘w‘.")
278 
279         try:
280             import bz2
281         except ImportError:
282             raise CompressionError("bz2 module is not available")
283 
284         if fileobj is not None:
285             fileobj = _BZ2Proxy(fileobj, mode)
286         else:
287             fileobj = bz2.BZ2File(name, mode, compresslevel=compresslevel)
288 
289         try:
290             t = cls.taropen(name, mode, fileobj, **kwargs)
291         except (IOError, EOFError):
292             fileobj.close()
293             if mode == ‘r‘:
294                 raise ReadError("not a bzip2 file")
295             raise
296         except:
297             fileobj.close()
298             raise
299         t._extfileobj = False
300         return t
301 
302     # All *open() methods are registered here.
303     OPEN_METH = {
304         "tar": "taropen",   # uncompressed tar
305         "gz":  "gzopen",    # gzip compressed tar
306         "bz2": "bz2open"    # bzip2 compressed tar
307     }
308 
309     #--------------------------------------------------------------------------
310     # The public methods which TarFile provides:
311 
312     def close(self):
313         """Close the TarFile. In write-mode, two finishing zero blocks are
314            appended to the archive.
315         """
316         if self.closed:
317             return
318 
319         if self.mode in "aw":
320             self.fileobj.write(NUL * (BLOCKSIZE * 2))
321             self.offset += (BLOCKSIZE * 2)
322             # fill up the end with zero-blocks
323             # (like option -b20 for tar does)
324             blocks, remainder = divmod(self.offset, RECORDSIZE)
325             if remainder > 0:
326                 self.fileobj.write(NUL * (RECORDSIZE - remainder))
327 
328         if not self._extfileobj:
329             self.fileobj.close()
330         self.closed = True
331 
332     def getmember(self, name):
333         """Return a TarInfo object for member `name‘. If `name‘ can not be
334            found in the archive, KeyError is raised. If a member occurs more
335            than once in the archive, its last occurrence is assumed to be the
336            most up-to-date version.
337         """
338         tarinfo = self._getmember(name)
339         if tarinfo is None:
340             raise KeyError("filename %r not found" % name)
341         return tarinfo
342 
343     def getmembers(self):
344         """Return the members of the archive as a list of TarInfo objects. The
345            list has the same order as the members in the archive.
346         """
347         self._check()
348         if not self._loaded:    # if we want to obtain a list of
349             self._load()        # all members, we first have to
350                                 # scan the whole archive.
351         return self.members
352 
353     def getnames(self):
354         """Return the members of the archive as a list of their names. It has
355            the same order as the list returned by getmembers().
356         """
357         return [tarinfo.name for tarinfo in self.getmembers()]
358 
359     def gettarinfo(self, name=None, arcname=None, fileobj=None):
360         """Create a TarInfo object for either the file `name‘ or the file
361            object `fileobj‘ (using os.fstat on its file descriptor). You can
362            modify some of the TarInfo‘s attributes before you add it using
363            addfile(). If given, `arcname‘ specifies an alternative name for the
364            file in the archive.
365         """
366         self._check("aw")
367 
368         # When fileobj is given, replace name by
369         # fileobj‘s real name.
370         if fileobj is not None:
371             name = fileobj.name
372 
373         # Building the name of the member in the archive.
374         # Backward slashes are converted to forward slashes,
375         # Absolute paths are turned to relative paths.
376         if arcname is None:
377             arcname = name
378         drv, arcname = os.path.splitdrive(arcname)
379         arcname = arcname.replace(os.sep, "/")
380         arcname = arcname.lstrip("/")
381 
382         # Now, fill the TarInfo object with
383         # information specific for the file.
384         tarinfo = self.tarinfo()
385         tarinfo.tarfile = self
386 
387         # Use os.stat or os.lstat, depending on platform
388         # and if symlinks shall be resolved.
389         if fileobj is None:
390             if hasattr(os, "lstat") and not self.dereference:
391                 statres = os.lstat(name)
392             else:
393                 statres = os.stat(name)
394         else:
395             statres = os.fstat(fileobj.fileno())
396         linkname = ""
397 
398         stmd = statres.st_mode
399         if stat.S_ISREG(stmd):
400             inode = (statres.st_ino, statres.st_dev)
401             if not self.dereference and statres.st_nlink > 1 and 402                     inode in self.inodes and arcname != self.inodes[inode]:
403                 # Is it a hardlink to an already
404                 # archived file?
405                 type = LNKTYPE
406                 linkname = self.inodes[inode]
407             else:
408                 # The inode is added only if its valid.
409                 # For win32 it is always 0.
410                 type = REGTYPE
411                 if inode[0]:
412                     self.inodes[inode] = arcname
413         elif stat.S_ISDIR(stmd):
414             type = DIRTYPE
415         elif stat.S_ISFIFO(stmd):
416             type = FIFOTYPE
417         elif stat.S_ISLNK(stmd):
418             type = SYMTYPE
419             linkname = os.readlink(name)
420         elif stat.S_ISCHR(stmd):
421             type = CHRTYPE
422         elif stat.S_ISBLK(stmd):
423             type = BLKTYPE
424         else:
425             return None
426 
427         # Fill the TarInfo object with all
428         # information we can get.
429         tarinfo.name = arcname
430         tarinfo.mode = stmd
431         tarinfo.uid = statres.st_uid
432         tarinfo.gid = statres.st_gid
433         if type == REGTYPE:
434             tarinfo.size = statres.st_size
435         else:
436             tarinfo.size = 0L
437         tarinfo.mtime = statres.st_mtime
438         tarinfo.type = type
439         tarinfo.linkname = linkname
440         if pwd:
441             try:
442                 tarinfo.uname = pwd.getpwuid(tarinfo.uid)[0]
443             except KeyError:
444                 pass
445         if grp:
446             try:
447                 tarinfo.gname = grp.getgrgid(tarinfo.gid)[0]
448             except KeyError:
449                 pass
450 
451         if type in (CHRTYPE, BLKTYPE):
452             if hasattr(os, "major") and hasattr(os, "minor"):
453                 tarinfo.devmajor = os.major(statres.st_rdev)
454                 tarinfo.devminor = os.minor(statres.st_rdev)
455         return tarinfo
456 
457     def list(self, verbose=True):
458         """Print a table of contents to sys.stdout. If `verbose‘ is False, only
459            the names of the members are printed. If it is True, an `ls -l‘-like
460            output is produced.
461         """
462         self._check()
463 
464         for tarinfo in self:
465             if verbose:
466                 print filemode(tarinfo.mode),
467                 print "%s/%s" % (tarinfo.uname or tarinfo.uid,
468                                  tarinfo.gname or tarinfo.gid),
469                 if tarinfo.ischr() or tarinfo.isblk():
470                     print "%10s" % ("%d,%d" 471                                     % (tarinfo.devmajor, tarinfo.devminor)),
472                 else:
473                     print "%10d" % tarinfo.size,
474                 print "%d-%02d-%02d %02d:%02d:%02d" 475                       % time.localtime(tarinfo.mtime)[:6],
476 
477             print tarinfo.name + ("/" if tarinfo.isdir() else ""),
478 
479             if verbose:
480                 if tarinfo.issym():
481                     print "->", tarinfo.linkname,
482                 if tarinfo.islnk():
483                     print "link to", tarinfo.linkname,
484             print
485 
486     def add(self, name, arcname=None, recursive=True, exclude=None, filter=None):
487         """Add the file `name‘ to the archive. `name‘ may be any type of file
488            (directory, fifo, symbolic link, etc.). If given, `arcname‘
489            specifies an alternative name for the file in the archive.
490            Directories are added recursively by default. This can be avoided by
491            setting `recursive‘ to False. `exclude‘ is a function that should
492            return True for each filename to be excluded. `filter‘ is a function
493            that expects a TarInfo object argument and returns the changed
494            TarInfo object, if it returns None the TarInfo object will be
495            excluded from the archive.
496         """
497         self._check("aw")
498 
499         if arcname is None:
500             arcname = name
501 
502         # Exclude pathnames.
503         if exclude is not None:
504             import warnings
505             warnings.warn("use the filter argument instead",
506                     DeprecationWarning, 2)
507             if exclude(name):
508                 self._dbg(2, "tarfile: Excluded %r" % name)
509                 return
510 
511         # Skip if somebody tries to archive the archive...
512         if self.name is not None and os.path.abspath(name) == self.name:
513             self._dbg(2, "tarfile: Skipped %r" % name)
514             return
515 
516         self._dbg(1, name)
517 
518         # Create a TarInfo object from the file.
519         tarinfo = self.gettarinfo(name, arcname)
520 
521         if tarinfo is None:
522             self._dbg(1, "tarfile: Unsupported type %r" % name)
523             return
524 
525         # Change or exclude the TarInfo object.
526         if filter is not None:
527             tarinfo = filter(tarinfo)
528             if tarinfo is None:
529                 self._dbg(2, "tarfile: Excluded %r" % name)
530                 return
531 
532         # Append the tar header and data to the archive.
533         if tarinfo.isreg():
534             with bltn_open(name, "rb") as f:
535                 self.addfile(tarinfo, f)
536 
537         elif tarinfo.isdir():
538             self.addfile(tarinfo)
539             if recursive:
540                 for f in os.listdir(name):
541                     self.add(os.path.join(name, f), os.path.join(arcname, f),
542                             recursive, exclude, filter)
543 
544         else:
545             self.addfile(tarinfo)
546 
547     def addfile(self, tarinfo, fileobj=None):
548         """Add the TarInfo object `tarinfo‘ to the archive. If `fileobj‘ is
549            given, tarinfo.size bytes are read from it and added to the archive.
550            You can create TarInfo objects using gettarinfo().
551            On Windows platforms, `fileobj‘ should always be opened with mode
552            ‘rb‘ to avoid irritation about the file size.
553         """
554         self._check("aw")
555 
556         tarinfo = copy.copy(tarinfo)
557 
558         buf = tarinfo.tobuf(self.format, self.encoding, self.errors)
559         self.fileobj.write(buf)
560         self.offset += len(buf)
561 
562         # If there‘s data to follow, append it.
563         if fileobj is not None:
564             copyfileobj(fileobj, self.fileobj, tarinfo.size)
565             blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
566             if remainder > 0:
567                 self.fileobj.write(NUL * (BLOCKSIZE - remainder))
568                 blocks += 1
569             self.offset += blocks * BLOCKSIZE
570 
571         self.members.append(tarinfo)
572 
573     def extractall(self, path=".", members=None):
574         """Extract all members from the archive to the current working
575            directory and set owner, modification time and permissions on
576            directories afterwards. `path‘ specifies a different directory
577            to extract to. `members‘ is optional and must be a subset of the
578            list returned by getmembers().
579         """
580         directories = []
581 
582         if members is None:
583             members = self
584 
585         for tarinfo in members:
586             if tarinfo.isdir():
587                 # Extract directories with a safe mode.
588                 directories.append(tarinfo)
589                 tarinfo = copy.copy(tarinfo)
590                 tarinfo.mode = 0700
591             self.extract(tarinfo, path)
592 
593         # Reverse sort directories.
594         directories.sort(key=operator.attrgetter(‘name‘))
595         directories.reverse()
596 
597         # Set correct owner, mtime and filemode on directories.
598         for tarinfo in directories:
599             dirpath = os.path.join(path, tarinfo.name)
600             try:
601                 self.chown(tarinfo, dirpath)
602                 self.utime(tarinfo, dirpath)
603                 self.chmod(tarinfo, dirpath)
604             except ExtractError, e:
605                 if self.errorlevel > 1:
606                     raise
607                 else:
608                     self._dbg(1, "tarfile: %s" % e)
609 
610     def extract(self, member, path=""):
611         """Extract a member from the archive to the current working directory,
612            using its full name. Its file information is extracted as accurately
613            as possible. `member‘ may be a filename or a TarInfo object. You can
614            specify a different directory using `path‘.
615         """
616         self._check("r")
617 
618         if isinstance(member, basestring):
619             tarinfo = self.getmember(member)
620         else:
621             tarinfo = member
622 
623         # Prepare the link target for makelink().
624         if tarinfo.islnk():
625             tarinfo._link_target = os.path.join(path, tarinfo.linkname)
626 
627         try:
628             self._extract_member(tarinfo, os.path.join(path, tarinfo.name))
629         except EnvironmentError, e:
630             if self.errorlevel > 0:
631                 raise
632             else:
633                 if e.filename is None:
634                     self._dbg(1, "tarfile: %s" % e.strerror)
635                 else:
636                     self._dbg(1, "tarfile: %s %r" % (e.strerror, e.filename))
637         except ExtractError, e:
638             if self.errorlevel > 1:
639                 raise
640             else:
641                 self._dbg(1, "tarfile: %s" % e)
642 
643     def extractfile(self, member):
644         """Extract a member from the archive as a file object. `member‘ may be
645            a filename or a TarInfo object. If `member‘ is a regular file, a
646            file-like object is returned. If `member‘ is a link, a file-like
647            object is constructed from the link‘s target. If `member‘ is none of
648            the above, None is returned.
649            The file-like object is read-only and provides the following
650            methods: read(), readline(), readlines(), seek() and tell()
651         """
652         self._check("r")
653 
654         if isinstance(member, basestring):
655             tarinfo = self.getmember(member)
656         else:
657             tarinfo = member
658 
659         if tarinfo.isreg():
660             return self.fileobject(self, tarinfo)
661 
662         elif tarinfo.type not in SUPPORTED_TYPES:
663             # If a member‘s type is unknown, it is treated as a
664             # regular file.
665             return self.fileobject(self, tarinfo)
666 
667         elif tarinfo.islnk() or tarinfo.issym():
668             if isinstance(self.fileobj, _Stream):
669                 # A small but ugly workaround for the case that someone tries
670                 # to extract a (sym)link as a file-object from a non-seekable
671                 # stream of tar blocks.
672                 raise StreamError("cannot extract (sym)link as file object")
673             else:
674                 # A (sym)link‘s file object is its target‘s file object.
675                 return self.extractfile(self._find_link_target(tarinfo))
676         else:
677             # If there‘s no data associated with the member (directory, chrdev,
678             # blkdev, etc.), return None instead of a file object.
679             return None
680 
681     def _extract_member(self, tarinfo, targetpath):
682         """Extract the TarInfo object tarinfo to a physical
683            file called targetpath.
684         """
685         # Fetch the TarInfo object for the given name
686         # and build the destination pathname, replacing
687         # forward slashes to platform specific separators.
688         targetpath = targetpath.rstrip("/")
689         targetpath = targetpath.replace("/", os.sep)
690 
691         # Create all upper directories.
692         upperdirs = os.path.dirname(targetpath)
693         if upperdirs and not os.path.exists(upperdirs):
694             # Create directories that are not part of the archive with
695             # default permissions.
696             os.makedirs(upperdirs)
697 
698         if tarinfo.islnk() or tarinfo.issym():
699             self._dbg(1, "%s -> %s" % (tarinfo.name, tarinfo.linkname))
700         else:
701             self._dbg(1, tarinfo.name)
702 
703         if tarinfo.isreg():
704             self.makefile(tarinfo, targetpath)
705         elif tarinfo.isdir():
706             self.makedir(tarinfo, targetpath)
707         elif tarinfo.isfifo():
708             self.makefifo(tarinfo, targetpath)
709         elif tarinfo.ischr() or tarinfo.isblk():
710             self.makedev(tarinfo, targetpath)
711         elif tarinfo.islnk() or tarinfo.issym():
712             self.makelink(tarinfo, targetpath)
713         elif tarinfo.type not in SUPPORTED_TYPES:
714             self.makeunknown(tarinfo, targetpath)
715         else:
716             self.makefile(tarinfo, targetpath)
717 
718         self.chown(tarinfo, targetpath)
719         if not tarinfo.issym():
720             self.chmod(tarinfo, targetpath)
721             self.utime(tarinfo, targetpath)
722 
723     #--------------------------------------------------------------------------
724     # Below are the different file methods. They are called via
725     # _extract_member() when extract() is called. They can be replaced in a
726     # subclass to implement other functionality.
727 
728     def makedir(self, tarinfo, targetpath):
729         """Make a directory called targetpath.
730         """
731         try:
732             # Use a safe mode for the directory, the real mode is set
733             # later in _extract_member().
734             os.mkdir(targetpath, 0700)
735         except EnvironmentError, e:
736             if e.errno != errno.EEXIST:
737                 raise
738 
739     def makefile(self, tarinfo, targetpath):
740         """Make a file called targetpath.
741         """
742         source = self.extractfile(tarinfo)
743         try:
744             with bltn_open(targetpath, "wb") as target:
745                 copyfileobj(source, target)
746         finally:
747             source.close()
748 
749     def makeunknown(self, tarinfo, targetpath):
750         """Make a file from a TarInfo object with an unknown type
751            at targetpath.
752         """
753         self.makefile(tarinfo, targetpath)
754         self._dbg(1, "tarfile: Unknown file type %r, " 755                      "extracted as regular file." % tarinfo.type)
756 
757     def makefifo(self, tarinfo, targetpath):
758         """Make a fifo called targetpath.
759         """
760         if hasattr(os, "mkfifo"):
761             os.mkfifo(targetpath)
762         else:
763             raise ExtractError("fifo not supported by system")
764 
765     def makedev(self, tarinfo, targetpath):
766         """Make a character or block device called targetpath.
767         """
768         if not hasattr(os, "mknod") or not hasattr(os, "makedev"):
769             raise ExtractError("special devices not supported by system")
770 
771         mode = tarinfo.mode
772         if tarinfo.isblk():
773             mode |= stat.S_IFBLK
774         else:
775             mode |= stat.S_IFCHR
776 
777         os.mknod(targetpath, mode,
778                  os.makedev(tarinfo.devmajor, tarinfo.devminor))
779 
780     def makelink(self, tarinfo, targetpath):
781         """Make a (symbolic) link called targetpath. If it cannot be created
782           (platform limitation), we try to make a copy of the referenced file
783           instead of a link.
784         """
785         if hasattr(os, "symlink") and hasattr(os, "link"):
786             # For systems that support symbolic and hard links.
787             if tarinfo.issym():
788                 if os.path.lexists(targetpath):
789                     os.unlink(targetpath)
790                 os.symlink(tarinfo.linkname, targetpath)
791             else:
792                 # See extract().
793                 if os.path.exists(tarinfo._link_target):
794                     if os.path.lexists(targetpath):
795                         os.unlink(targetpath)
796                     os.link(tarinfo._link_target, targetpath)
797                 else:
798                     self._extract_member(self._find_link_target(tarinfo), targetpath)
799         else:
800             try:
801                 self._extract_member(self._find_link_target(tarinfo), targetpath)
802             except KeyError:
803                 raise ExtractError("unable to resolve link inside archive")
804 
805     def chown(self, tarinfo, targetpath):
806         """Set owner of targetpath according to tarinfo.
807         """
808         if pwd and hasattr(os, "geteuid") and os.geteuid() == 0:
809             # We have to be root to do so.
810             try:
811                 g = grp.getgrnam(tarinfo.gname)[2]
812             except KeyError:
813                 g = tarinfo.gid
814             try:
815                 u = pwd.getpwnam(tarinfo.uname)[2]
816             except KeyError:
817                 u = tarinfo.uid
818             try:
819                 if tarinfo.issym() and hasattr(os, "lchown"):
820                     os.lchown(targetpath, u, g)
821                 else:
822                     if sys.platform != "os2emx":
823                         os.chown(targetpath, u, g)
824             except EnvironmentError, e:
825                 raise ExtractError("could not change owner")
826 
827     def chmod(self, tarinfo, targetpath):
828         """Set file permissions of targetpath according to tarinfo.
829         """
830         if hasattr(os, ‘chmod‘):
831             try:
832                 os.chmod(targetpath, tarinfo.mode)
833             except EnvironmentError, e:
834                 raise ExtractError("could not change mode")
835 
836     def utime(self, tarinfo, targetpath):
837         """Set modification time of targetpath according to tarinfo.
838         """
839         if not hasattr(os, ‘utime‘):
840             return
841         try:
842             os.utime(targetpath, (tarinfo.mtime, tarinfo.mtime))
843         except EnvironmentError, e:
844             raise ExtractError("could not change modification time")
845 
846     #--------------------------------------------------------------------------
847     def next(self):
848         """Return the next member of the archive as a TarInfo object, when
849            TarFile is opened for reading. Return None if there is no more
850            available.
851         """
852         self._check("ra")
853         if self.firstmember is not None:
854             m = self.firstmember
855             self.firstmember = None
856             return m
857 
858         # Read the next block.
859         self.fileobj.seek(self.offset)
860         tarinfo = None
861         while True:
862             try:
863                 tarinfo = self.tarinfo.fromtarfile(self)
864             except EOFHeaderError, e:
865                 if self.ignore_zeros:
866                     self._dbg(2, "0x%X: %s" % (self.offset, e))
867                     self.offset += BLOCKSIZE
868                     continue
869             except InvalidHeaderError, e:
870                 if self.ignore_zeros:
871                     self._dbg(2, "0x%X: %s" % (self.offset, e))
872                     self.offset += BLOCKSIZE
873                     continue
874                 elif self.offset == 0:
875                     raise ReadError(str(e))
876             except EmptyHeaderError:
877                 if self.offset == 0:
878                     raise ReadError("empty file")
879             except TruncatedHeaderError, e:
880                 if self.offset == 0:
881                     raise ReadError(str(e))
882             except SubsequentHeaderError, e:
883                 raise ReadError(str(e))
884             break
885 
886         if tarinfo is not None:
887             self.members.append(tarinfo)
888         else:
889             self._loaded = True
890 
891         return tarinfo
892 
893     #--------------------------------------------------------------------------
894     # Little helper methods:
895 
896     def _getmember(self, name, tarinfo=None, normalize=False):
897         """Find an archive member by name from bottom to top.
898            If tarinfo is given, it is used as the starting point.
899         """
900         # Ensure that all members have been loaded.
901         members = self.getmembers()
902 
903         # Limit the member search list up to tarinfo.
904         if tarinfo is not None:
905             members = members[:members.index(tarinfo)]
906 
907         if normalize:
908             name = os.path.normpath(name)
909 
910         for member in reversed(members):
911             if normalize:
912                 member_name = os.path.normpath(member.name)
913             else:
914                 member_name = member.name
915 
916             if name == member_name:
917                 return member
918 
919     def _load(self):
920         """Read through the entire archive file and look for readable
921            members.
922         """
923         while True:
924             tarinfo = self.next()
925             if tarinfo is None:
926                 break
927         self._loaded = True
928 
929     def _check(self, mode=None):
930         """Check if TarFile is still open, and if the operation‘s mode
931            corresponds to TarFile‘s mode.
932         """
933         if self.closed:
934             raise IOError("%s is closed" % self.__class__.__name__)
935         if mode is not None and self.mode not in mode:
936             raise IOError("bad operation for mode %r" % self.mode)
937 
938     def _find_link_target(self, tarinfo):
939         """Find the target member of a symlink or hardlink member in the
940            archive.
941         """
942         if tarinfo.issym():
943             # Always search the entire archive.
944             linkname = "/".join(filter(None, (os.path.dirname(tarinfo.name), tarinfo.linkname)))
945             limit = None
946         else:
947             # Search the archive before the link, because a hard link is
948             # just a reference to an already archived file.
949             linkname = tarinfo.linkname
950             limit = tarinfo
951 
952         member = self._getmember(linkname, tarinfo=limit, normalize=True)
953         if member is None:
954             raise KeyError("linkname %r not found" % linkname)
955         return member
956 
957     def __iter__(self):
958         """Provide an iterator object.
959         """
960         if self._loaded:
961             return iter(self.members)
962         else:
963             return TarIter(self)
964 
965     def _dbg(self, level, msg):
966         """Write debugging output to sys.stderr.
967         """
968         if level <= self.debug:
969             print >> sys.stderr, msg
970 
971     def __enter__(self):
972         self._check()
973         return self
974 
975     def __exit__(self, type, value, traceback):
976         if type is None:
977             self.close()
978         else:
979             # An exception occurred. We must not call close() because
980             # it would try to write end-of-archive blocks and padding.
981             if not self._extfileobj:
982                 self.fileobj.close()
983             self.closed = True
984 # class TarFile

 1 <?xml version="1.0"?>
 2 <data>
 3     <country name="Liechtenstein">
 4         <rank updated="yes">2</rank>
 5         <year>2008</year>
 6         <gdppc>141100</gdppc>
 7         <neighbor name="Austria" direction="E"/>
 8         <neighbor name="Switzerland" direction="W"/>
 9     </country>
10     <country name="Singapore">
11         <rank updated="yes">5</rank>
12         <year>2011</year>
13         <gdppc>59900</gdppc>
14         <neighbor name="Malaysia" direction="N"/>
15     </country>
16     <country name="Panama">
17         <rank updated="yes">69</rank>
18         <year>2011</year>
19         <gdppc>13600</gdppc>
20         <neighbor name="Costa Rica" direction="W"/>
21         <neighbor name="Colombia" direction="E"/>
22     </country>
23 </data>