code: def sys_rename(self, oldnamep, newnamep):
          
          oldname = self.current.read_string(oldnamep)
          newname = self.current.read_string(newnamep)
  
          ret = 0
          try:
              os.rename(oldname, newname)
          except OSError as e:
              ret = -e.errno
  
          return ret
docs: Rename filename `oldnamep` to `newnamep`.
  
          :param int oldnamep: pointer to oldname
          :param int newnamep: pointer to newname