Implementing a clone of *nix tree in Ruby

01_tree.rb

# encoding: utf-8

# Build a Hash tree from Array Of file names
#
def build_hash_tree(filenames)
  files_tree = filenames.inject({}) { |h, i| t = h; i.split("/").each { |n| t[n] ||= {}; t = t[n] }; h }
end

# Box-drawing character - https://en.wikipedia.org/wiki/Box-drawing_character
# ├  └  ─  │
# 
def display_tree(files_tree, level = -1, branches = [])
  tab = ' ' * 4
  level += 1

  files_tree.each_with_index do |(key, val), index|
    if val.empty? # this is a file
      result = branches.take(level).inject('') { |s, i| s << (i == 1 ? '│   ': '    ') }

      if index == files_tree.length - 1
        # this is a last element
        result << '└' + '── ' + key
      else
        result << '├' + '── ' + key
      end

      puts result
    else # this is directory
      if key == '' # root directory
        result = '.'
      else
        result = branches.take(level).inject('') { |s, i| s << (i == 1 ? '│   ': '    ') }
        if index == files_tree.length - 1
          # this is a last element
          result << '└' + '── ' + key

          branches[level] = 0
        else
          result << '├' + '── ' + key

          branches[level] = 1
        end
      end
      puts result

      # recursion \(^_^)/
      display_tree(val, level, branches)
    end
  end
end

files = Dir['**/*']

# list/sort files before folders in a directory listing
files = files.map { |file| [file.count("/"), file] }
files = files.sort.reverse.map { |file| file[1] }

files_tree = build_hash_tree(files)

display_tree(files_tree)

02_output.txt

$ ruby tree.rb 
├── lib
│   ├── crowdin-api
│   │   ├── version.rb
│   │   ├── methods.rb
│   │   └── errors.rb
│   └── crowdin-api.rb
├── examples
│   ├── tree.rb
│   ├── project_info.rb
│   ├── directory_tree.rb
│   ├── Gemfile.lock
│   └── Gemfile
├── crowdin-api.gemspec
├── Rakefile
├── README.md
├── LICENSE
├── Gemfile.lock
└── Gemfile

Nice) But whey just not to use tree ? 0_o

This script was originally written to list the contents of directories in a tree-like format received from the external API (I had just an Array of file names). As I found out later this code is suitable for use with Dir.glob :)