code: def main(argv=None):
      """Tiffcomment command line usage main function."""
      if argv is None:
          argv = sys.argv
  
      if len(argv) > 2 and argv[1] in "--set":
          comment = argv[2]
          files = argv[3:]
      else:
          comment = None
          files = argv[1:]
  
      if len(files) == 0 or any(f.startswith("-") for f in files):
          print()
          print(__doc__.strip())
          return
  
      if comment is None:
          pass
      elif os.path.exists(comment):
          with open(comment, "rb") as fh:
              comment = fh.read()
      else:
          try:
              comment = comment.encode("ascii")
          except UnicodeEncodeError as exc:
              print(f"{exc}")
              comment = comment.encode()
  
      for file in files:
          try:
              result = tiffcomment(file, comment)
          except Exception as exc:
              print(f"{file}: {exc}")
          else:
              if result:
                  print(result)
  
label_desc: Use image node_id 1 for calling a global function with example usage: main(argv) without return types