backlight

#!/sbin/openrc-run

cachedir="/var/cache/backlight";
cards="$(basename -a /sys/class/backlight/*)";

if [ ! -d $cachedir ]; then
    mkdir -p $cachedir;
fi

for card in $cards; do
    if [ ! -f $cachedir/$card ]; then
        cat /sys/class/backlight/$card/brightness > $cachedir/$card;
    fi
done

start() {
    ebegin "Restoring screen brightness";
    for card in $cards; do
        local cache_value=$(cat $cachedir/$card);
        if [ $cache_value -ne 0 ]; then
            printf $cache_value > /sys/class/backlight/$card/brightness;
        else
            ewarn "Brightness should not zero, aborting ...";
            return 3;
        fi
    done
    return 0;
}

stop() {
    ebegin "Saving screen brightness";
    for card in $cards; do
        cat /sys/class/backlight/$card/brightness > $cachedir/$card;
    done
    return 0;
}