title: Extract Tar File inside Memory Filesystem
body: <p>I have trouble using memoryfs:
  <a href="https://docs.pyfilesystem.org/en/latest/reference/memoryfs.html" rel="nofollow noreferrer">https://docs.pyfilesystem.org/en/latest/reference/memoryfs.html</a>:</p>
  
  <p>I'm trying to extract tar inside a memoryFS, but I cant use mem_fs because it is an object and cant get the real / memory path...</p>
  
  <pre><code>from fs import open_fs, copy
  import fs
  import tarfile
  
  mem_fs = open_fs('mem://')
  
  print(mem_fs.isempty('.'))
  
  fs.copy.copy_file('//TEST_FS', 'test.tar', mem_fs, 'test.tar')
  
  print(mem_fs.listdir('/'))
  
  with mem_fs.open('test.tar') as tar_file:
      print(tar_file.read())
      tar = tarfile.open(tar_file) // I cant create the tar ...
      tar.extractall(mem_fs + 'Extract_Dir') // Cant extract it too...
  </code></pre>
  
  <p>Can someone help me, it is possible to do that ?</p>