code: def _search_for_dag_file(val: str | None) -> str | None:
      """
      Search for the file referenced at fileloc.
  
      By the time we get to this function, we've already run this `val` through `process_subdir`
      and loaded the DagBag there and came up empty.  So here, if `val` is a file path, we make
      a last ditch effort to try and find a dag file with the same name in our dags folder. (This
      avoids the unnecessary dag parsing that would occur if we just parsed the dags folder).
  
      If `val` is a path to a file, this likely means that the serializing process had a dags_folder
      equal to only the dag file in question. This prevents us from determining the relative location.
      And if the paths are different between worker and dag processor / scheduler, then we won't find
      the dag at the given location.
      """
      if val and Path(val).suffix in (".zip", ".py"):
          matches = list(
              Path(settings.DAGS_FOLDER).rglob(Path(val).name)
          )
          if len(matches) == 1:
              return matches[0].as_posix()
      return None
  
imports: from __future__ import annotations
  import functools
  import logging
  import os
  import socket
  import sys
  import threading
  import traceback
  import warnings
  from argparse import Namespace
  from datetime import datetime
  from pathlib import Path
  from typing import TYPE_CHECKING, Callable, TypeVar, cast
  import re2
  from sqlalchemy import select
  from airflow import settings
  from airflow.exceptions import AirflowException, RemovedInAirflow3Warning
  from airflow.utils import cli_action_loggers
  from airflow.utils.log.non_caching_file_handler import NonCachingFileHandler
  from airflow.utils.platform import getuser, is_terminal_support_colors
  from airflow.utils.session import NEW_SESSION, provide_session
label_desc: Use image node_id 6 for calling a global function with example usage: _search_for_dag_file(val) and returns: None, matches