鼠标几秒钟后关闭（Ubuntu 13.10，Windows 8.1）

Question

我试过了lsusb，我可以在列表中看到我的鼠标。

我试过

for foo in /sys/bus/usb/devices/*/power/level;
> do echo on > $foo;
> done

但我收到了这个回复

bash: /sys/bus/usb/devices/1-4/power/level: Permission denied
bash: /sys/bus/usb/devices/2-2/power/level: Permission denied
bash: /sys/bus/usb/devices/5-1/power/level: Permission denied
bash: /sys/bus/usb/devices/5-3/power/level: Permission denied
bash: /sys/bus/usb/devices/usb1/power/level: Permission denied
bash: /sys/bus/usb/devices/usb2/power/level: Permission denied
bash: /sys/bus/usb/devices/usb3/power/level: Permission denied
bash: /sys/bus/usb/devices/usb4/power/level: Permission denied
bash: /sys/bus/usb/devices/usb5/power/level: Permission denied
bash: /sys/bus/usb/devices/usb6/power/level: Permission denied

请注意，只有当我的笔记本电脑拔下电源时才会发生这种情况。

Answer 1

你的代码应该是，

for i in /sys/bus/usb/devices/*/power/level; do sudo echo on > $i; done

或者

for i in /sys/bus/usb/devices/*/power/level; do sudo sh -c "echo on > $i"; done