Update cuda.md

Author: ZhikangNiu

src/ai/cuda.md

@@ -5,8 +5,23 @@
 - [pybind11 documentation](https://pybind11.readthedocs.io/en/stable/basics.html)
 - [Using pybind11](https://people.duke.edu/~ccc14/sta-663-2016/18G_C++_Python_pybind11.html)
 - [Use pybind11 for a detailed but simple example](https://iamsorush.com/posts/pybind11-robot/)
-- 切换CUDA版本步骤: [[CSDN](https://blog.csdn.net/u013905398/article/details/103799621)]
 - 查看你的显卡的情况:
   - nvitop: [[Github](https://github.com/XuehaiPan/nvitop)]
   - gpustat: [[Github](https://github.com/wookayin/gpustat)]
   - nvidia-smi
+- - 切换CUDA版本步骤
+  - 删除软连接
+    ```shell
+    cd /usr/local
+    ls -l cuda #查看cuda的软链接
+    sudo rm -rf cuda
+    sudo ln -s /usr/local/cuda-10.0 /usr/local/cuda # 更换为对应的cuda
+    ```
+  - 添加环境变量
+    ```shell
+    # 假设你使用的是bash，那么你需要打开.bashrc
+    export PATH="/usr/local/cuda-10.0/bin:$PATH"
+    export LD_LIBRARY_PATH="/usr/local/cuda-10.0/lib64:$LD_LIBRARY_PATH"
+    export CUDA_HOME=/usr/local/cuda
+    ```
+    在完成上述步骤后，你需要 source ~/.bashrc