system.py 文件源码

def _set_argv(process_name):
  """
  Overwrites our argv in a similar fashion to how it's done in C with:
  strcpy(argv[0], 'new_name');
  """

  if Py_GetArgcArgv is None:
    return

  global _PROCESS_NAME

  # both gets the current process name and initializes _MAX_NAME_LENGTH

  current_name = get_process_name()

  argv, argc = ctypes.c_int(0), argc_t()
  Py_GetArgcArgv(argv, ctypes.pointer(argc))

  if len(process_name) > _MAX_NAME_LENGTH:
    raise IOError("Can't rename process to something longer than our initial name (this would overwrite memory used for the env)")

  # space we need to clear
  zero_size = max(len(current_name), len(process_name))

  ctypes.memset(argc.contents, 0, zero_size + 1)  # null terminate the string's end
  process_name_encoded = process_name.encode('utf8')
  ctypes.memmove(argc.contents, process_name_encoded, len(process_name))
  _PROCESS_NAME = process_name