import hashlib

def sha256_of_file(filepath):
    sha256 = hashlib.sha256()
    with open(filepath, "rb") as f:
        # 分块读取，避免大文件占用太多内存
        for chunk in iter(lambda: f.read(8192), b""):
            sha256.update(chunk)
    return sha256.hexdigest()

# 示例
file_path = "ntool.cmd"
print(f"{file_path} 的 SHA256: {sha256_of_file(file_path)}")