text: """Utilities for extracting common archive formats"""
  
  import zipfile
  import tarfile
  import os
  import shutil
  import posixpath
  import contextlib
  from distutils.errors import DistutilsError
  
  from pkg_resources import ensure_directory
  
  __all__ = [
      "unpack_archive", "unpack_zipfile", "unpack_tarfile", "default_filter",
      "UnrecognizedFormat", "extraction_drivers", "unpack_directory",
  ]
  
  
  class UnrecognizedFormat(DistutilsError):
      """Couldn't recognize the archive type"""
  
  
  def default_filter(src, dst):
      """The default progress/filter callback; returns True for all files"""
      return dst
  
  
  def unpack_archive(filename, extract_dir, progress_filter=default_filter,
          drivers=None):
      """Unpack `filename` to `extract_dir`, or raise ``UnrecognizedFormat``
  
      `progress_filter` is a function taking two arguments: a source path
      internal to the archive ('/'-separated), and a filesystem path where it
      will be extracted.  The callback must return the desired extract path
      (which may be the same as the one passed in), or else ``None`` to skip
      that file or directory.  The callback can thus be used to report on the
      progress of the extraction, as well as to filter the items extracted or
      alter their extraction paths.
  
      `drivers`, if supplied, must be a non-empty sequence of functions with the
      same signature as this function (minus the `drivers` argument), that raise
      ``UnrecognizedFormat`` if they do not support extracting the designated
      archive type.  The `drivers` are tried in sequence until one is found that
      does not raise an error, or until all are exhausted (in which case
      ``UnrecognizedFormat`` is raised).  If you do not supply a sequence of
      drivers, the module's ``extraction_drivers`` constant will be used, which
      means that ``unpack_zipfile`` and ``unpack_tarfile`` will be tried, in that
      order.
      """
      for driver in drivers or extraction_drivers:
          try:
              driver(filename, extract_dir, progress_filter)
          except UnrecognizedFormat:
              continue
          else:
              return
      else:
          raise UnrecognizedFormat(
              "Not a recognized archive type: %s" % filename
          )
  
  
  def unpack_directory(filename, extract_dir, progress_filter=default_filter):
      """"Unpack" a directory, using the same interface as for archives
  
      Raises ``UnrecognizedFormat`` if `filename` is not a directory
      """
      if not os.path.isdir(filename):
          raise UnrecognizedFormat("%s is not a directory" % filename)
  
      paths = {
          filename: ('', extract_dir),
      }
      for base, dirs, files in os.walk(filename):
          src, dst = paths[base]
          for d in dirs:
              paths[os.path.join(base, d)] = src + d + '/', os.path.join(dst, d)
          for f in files:
              target = os.path.join(dst, f)
              target = progress_filter(src + f, target)
              if not target:
                  # skip non-files
                  continue
              ensure_directory(target)
              f = os.path.join(base, f)
              shutil.copyfile(f, target)
              shutil.copystat(f, target)
  
  
  def unpack_zipfile(filename, extract_dir, progress_filter=default_filter):
      """Unpack zip `filename` to `extract_dir`
  
      Raises ``UnrecognizedFormat`` if `filename` is not a zipfile (as determined
      by ``zipfile.is_zipfile()``).  See ``unpack_archive()`` for an explanation
      of the `progress_filter` argument.
      """
  
      if not zipfile.is_zipfile(filename):
          raise UnrecognizedFormat("%s is not a zip file" % (filename,))
  
      with zipfile.ZipFile(filename) as z:
          for info in z.infolist():
              name = info.filename
  
              # don't extract absolute paths or ones with .. in them
              if name.startswith('/') or '..' in name.split('/'):
                  continue
  
              target = os.path.join(extract_dir, *name.split('/'))
              target = progress_filter(name, target)
              if not target:
                  continue
              if name.endswith('/'):
                  # directory
                  ensure_directory(target)
              else:
                  # file
                  ensure_directory(target)
                  data = z.read(info.filename)
                  with open(target, 'wb') as f:
                      f.write(data)
              unix_attributes = info.external_attr >> 16
              if unix_attributes:
                  os.chmod(target, unix_attributes)
  
  
  def unpack_tarfile(filename, extract_dir, progress_filter=default_filter):
      """Unpack tar/tar.gz/tar.bz2 `filename` to `extract_dir`
  
      Raises ``UnrecognizedFormat`` if `filename` is not a tarfile (as determined
      by ``tarfile.open()``).  See ``unpack_archive()`` for an explanation
      of the `progress_filter` argument.
      """
      try:
          tarobj = tarfile.open(filename)
      except tarfile.TarError:
          raise UnrecognizedFormat(
              "%s is not a compressed or uncompressed tar file" % (filename,)
          )
      with contextlib.closing(tarobj):
          # don't do any chowning!
          tarobj.chown = lambda *args: None
          for member in tarobj:
              name = member.name
              # don't extract absolute paths or ones with .. in them
              if not name.startswith('/') and '..' not in name.split('/'):
                  prelim_dst = os.path.join(extract_dir, *name.split('/'))
  
                  # resolve any links and to extract the link targets as normal
                  # files
                  while member is not None and (member.islnk() or member.issym()):
                      linkpath = member.linkname
                      if member.issym():
                          base = posixpath.dirname(member.name)
                          linkpath = posixpath.join(base, linkpath)
                          linkpath = posixpath.normpath(linkpath)
                      member = tarobj._getmember(linkpath)
  
                  if member is not None and (member.isfile() or member.isdir()):
                      final_dst = progress_filter(name, prelim_dst)
                      if final_dst:
                          if final_dst.endswith(os.sep):
                              final_dst = final_dst[:-1]
                          try:
                              # XXX Ugh
                              tarobj._extract_member(member, final_dst)
                          except tarfile.ExtractError:
                              # chown/chmod/mkfifo/mknode/makedev failed
                              pass
          return True
  
  
  extraction_drivers = unpack_directory, unpack_zipfile, unpack_tarfile
  