cdu, cdd: cd up/down lots of empty directories, useful for navigating Java, Scala etc. code trees

cdd.sh

function cd_down_rec () {
    case $(find ./* -maxdepth 0 -type d -not -name ".*" | wc -l) in
    1)
        cd *
        cd_down_rec
        ;; 
    *)
        ;;
    esac   
}

function cd_up_rec () {
    cd ..
    case $(find ./* -maxdepth 0 -type d -not -name ".*" | wc -l) in
    1)
        cd_up_rec
        ;; 
    *)
        ;;
    esac   
}

dotdot () {
    l=$1
    if [[ $l -gt 0 ]] ; then
        echo -n "../"; dotdot $(expr $l - 1)
    fi
}

function cdd () {
    path=$1
    if [[ $path != "" && -e $path ]]; then
        cd $path
    fi
    cd_down_rec
}

function cdu () {
    levels=$1
    case $levels in
    "")
        cd_up_rec
        ;;
    *)
        path=$(dotdot $levels)
        cd $path
        ;;
    esac
}