# Mac 解决 "Operation not permitted" 权限问题

```
chmod: Unable to change file mode on /usr/bin/cc: Operation not permitted
```

发现是El Capitan（10.11） 加入了Rootless机制，很多系统目录不再能够随心所欲的读写了，即使设置 root 权限也不行。

以下路径无法写和执行

```
/System
/bin
/sbin
/usr (except /usr/local)
```

加入这个机制主要是为了防止恶意程序的入侵，更多我们可以查看官网

<https://developer.apple.com/videos/play/wwdc2015/706/>

* 如何关闭

  重启按住 Command+R，进入恢复模式，打开Terminal

`csrutil disable`

* 如何开启

  重启按住 Command+R，进入恢复模式，打开Terminal。

`csrutil enable`


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