code: def find_matching_symlink(path, source):
      
      def to_abs(target):
          if os.path.isabs(target):
              return target
          else:
              return os.path.normpath(os.path.join(path, target))
  
      abs_source = to_abs(source)
  
      for name in os.listdir(path):
          linkpath = os.path.join(path, name)
          if os.path.islink:
              source_ = os.readlink(linkpath)
              if to_abs(source_) == abs_source:
                  return name
  
      return None
docs: Find a symlink under `path` that points at `source`.
  
      If source is relative, it is considered relative to `path`.
  
      Returns:
          str: Name of symlink found, or None.