echo 255 > /sys/devices/platform/backlight/backlight/backlight/brightness//调整屏幕亮度
cat /sys/devices/platform/backlight/backlight/backlight/brightness//查看屏幕亮度
echo 4 > /sys/class/graphics/fb0/blank//息屏
echo 0 > /sys/class/graphics/fb0/blank//亮屏
//待机
echo "mem" > /sys/power/state
echo "disk" > /sys/power/state
//休眠
echo "platform" > /sys/power/disk
echo "shutdown" > /sys/power/disk
//关机
poweroff -f