new_contents: import os
  import shutil
  from pwd import getpwnam
  from grp import getgrnam
  
  
  # Files & directories --------------------------------------------------
  
  def mkdir(path, mode=0777, parents=False, uid=None, gid=None, force=False):
      """Create a directory with optional features
  
      Create a directory and optionaly set its permissions to mode and its
      owner and/or group. If path refers to an existing path, nothing is done
      unless force is True.
  
      Keyword arguments:
          - path -- The directory to create
          - mode -- Directory mode to set in octal
          - parents -- Make parent directories as needed
          - uid -- Numeric uid or user name
          - gid -- Numeric gid or group name
          - force -- Force directory creation and owning even if the path exists
  
      """
      if os.path.exists(path) and not force:
          return
      if parents:
          os.makedirs(path, mode)
      else:
          os.mkdir(path, mode)
      try:
          chown(path, uid, gid)
      except:
          pass
  
  
  def chown(path, uid=None, gid=None, recursive=False):
      """Change the owner and/or group of a path
  
      Keyword arguments:
          - uid -- Numeric uid or user name
          - gid -- Numeric gid or group name
          - recursive -- Operate on path recursively
  
      """
      if uid is None and gid is None:
          raise ValueError("either uid or gid argument is required")
  
      # Retrieve uid/gid
      if isinstance(uid, basestring):
          uid = getpwnam(uid).pw_uid
      elif uid is None:
          uid = -1
      if isinstance(gid, basestring):
          gid = getpwnam(gid).gr_gid
      elif gid is None:
          gid = -1
  
      os.chown(path, uid, gid)
      if recursive and os.path.isdir(path):
          for root, dirs, files in os.walk(path):
              for d in dirs:
                  os.chown(os.path.join(root, d), uid, gid)
              for f in files:
                  os.chown(os.path.join(root, f), uid, gid)
  
  
  def rm(path, recursive=False, force=False):
      """Remove a file or directory
  
      Keyword arguments:
          - path -- The path to remove
          - recursive -- Remove directories and their contents recursively
          - force -- Ignore nonexistent files
  
      """
      if recursive and os.path.isdir(path):
          shutil.rmtree(path, ignore_errors=force)
      else:
          try:
              os.remove(path)
          except OSError:
              if not force:
                  raise
  
subject: Add a filesystem utils closed to some coreutils commands