Mouse turns off after a few seconds (Ubuntu 13.10, Windows 8.1)

Question

I tried lsusb and I can see my mouse in the list.

I tried

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

But I got this reply

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

Note that this only happens whenever my laptop is unplugged.

Answer 1

Your code should be,

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

OR

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