macbook在linux背光键盘的脚本

#!/bin/bash
BACKLIGHT=$(cat /sys/class/leds/smc::kbd_backlight/brightness)
INCREMENT=15


if [ $UID -ne 0 ]; then
    echo "Please run this program as superuser"
    exit 1
fi


SET_VALUE=0


case $1 in


    up)
        TOTAL=`expr $BACKLIGHT + $INCREMENT`
        if [ $TOTAL -gt "255" ]; then
            exit 1
        fi
        SET_VALUE=1
        ;;
    down)
        TOTAL=`expr $BACKLIGHT - $INCREMENT`
        if [ $TOTAL -lt "0" ]; then
            exit 1
        fi
        SET_VALUE=1
        ;;
    total)
TEMP_VALUE=$BACKLIGHT
while [ $TEMP_VALUE -lt "255" ]; do
TEMP_VALUE=`expr $TEMP_VALUE + 1`
if [ $TEMP_VALUE -gt "255" ]; then TEMP_VALUE=255; fi
echo $TEMP_VALUE > /sys/class/leds/smc::kbd_backlight/brightness
done
        ;;
    off)
TEMP_VALUE=$BACKLIGHT
while [ $TEMP_VALUE -gt "0" ]; do
TEMP_VALUE=`expr $TEMP_VALUE - 1`
if [ $TEMP_VALUE -lt "0" ]; then TEMP_VALUE=0; fi
echo $TEMP_VALUE > /sys/class/leds/smc::kbd_backlight/brightness
done
        ;;
    *)
        echo "Use: keyboard-light up|down|total|off"
        ;;
esac


if [ $SET_VALUE -eq "1" ]; then
    echo $TOTAL > /sys/class/leds/smc::kbd_backlight/brightness
fi

==========
保存为keyboard-backlight.sh，放在/usr/local/bin.
用法:
keyboard-light up|down|total|off
每次up的值是15