Rakefile.rb

desc "read names"
task :read_names do
  @names = File.readlines "names"
  @names.each do |name|
    puts name
  end
end

desc "make class directory"
task :make_class_dir do
  make_directory "class"
end

desc "make student directories"
task :make_student_dirs => [:make_class_dir, :read_names] do
  @names.each do |name|
    make_directory "class/#{name.chomp}"
  end
end

def make_directory(name)
  Dir.mkdir name unless Dir.exists? name
end