tree utility in ruby

tree.rb

#!/usr/bin/env ruby

# tree.rb prints a directory tree.

# Prints a tree with all the descendants of path
# if path is a directory. If path is not a directory,
# does nothing.
def print_tree(path, prefix='')
  return unless File.directory?(path)
  Dir.entries(path).each_with_index do |entry, index|
    if entry != '.' and entry != '..'
      if index < Dir.entries(path).length - 1
        puts prefix + "├── #{entry}"
        print_tree(path + '/' + entry,
             prefix + '│   ')
      else
        puts prefix + "└── #{entry}"
        print_tree(path + '/' + entry,
             prefix + '    ')
      end
    end
  end
end

root = ARGV[0] || '.'
puts root
print_tree(root)