tree... in bash

tree.sh

#!/bin/sh

_tree() {
	IFS=$'\x0a'
	local dir len i d
	dir=($(ls "$1" --group-directories-first 2>/dev/null))
	len=${#dir[@]}

	for (( i = 0; i < len; i++ )); do
		if (( i == len - 1 )); then
			printf '%s└' "$2"
		else
			printf '%s├' "$2"
		fi

		d="${1}/${dir[i]}"

		if [ -d "$d" ]; then
			printf '── \e[1;34m%s\e[0m\n' "${dir[i]}"

			if (( i == len -1 )); then
				_tree "$d" "${2}    "
			else
				_tree "$d" "${2}│   "
			fi
		else
			printf '── %s\n' "${dir[i]}"
		fi
	done

	unset IFS
}

if [ $# -lt 1 ]; then
	base="$PWD"
else
	base="$1"
fi

printf '\e[1;34m%s\e[0m\n' "$base"
_tree "$base"