| # SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved. | |
| # SPDX-License-Identifier: Apache-2.0 | |
| import os | |
| _TRUE_VALUES = frozenset({"1", "true", "yes", "on"}) | |
| _FALSE_VALUES = frozenset({"0", "false", "no", "off"}) | |
| def envvar_bool(name: str, default: bool = False) -> bool: | |
| """Read a bool-like environment variable. | |
| Unset, empty, or whitespace-only means ``default``. ``1/true/yes/on`` and | |
| ``0/false/no/off`` are recognised case-insensitively, and any other integer | |
| follows C truthiness, so ``2`` is true and ``-0`` is false. | |
| A value that is none of those keeps the historical set-means-true | |
| behaviour rather than raising, because these variables are read during | |
| import and a raise would turn a typo into an import failure. | |
| """ | |
| raw = os.environ.get(name) | |
| if raw is None: | |
| return default | |
| raw = raw.strip() | |
| if not raw: | |
| return default | |
| lowered = raw.lower() | |
| if lowered in _TRUE_VALUES: | |
| return True | |
| if lowered in _FALSE_VALUES: | |
| return False | |
| try: | |
| return int(raw, 0) != 0 | |
| except ValueError: | |
| return True | |