### Directory aliases
#  e.x.
#    $ hash -d hoge=/to/path
#    $ ls ~hoge
set_hash_in_links() {
    local links=~/links
    [ ! -d "$links" ] && return 0
    [ $(command ls -1 "$links" | wc -l) -eq 0 ] && return 0
    local src
    local target
    for target in "$links"/*; do
        src=$(basename "$target")
        case `uname -s` in
            Darwin|FreeBSD)
                target=$(readlink -n $target)
                ;;
            *)
                target=$(readlink -fq $target)
                ;;
        esac
        [ -n "$target" ] && hash -d $src="$target"
    done
}
set_hash_in_links