Measure how much memory gets used by a Ruby process

memory.rb

def print_memory_usage
  memory_before = `ps -o rss= -p #{Process.pid}`.to_i
  yield
  memory_after = `ps -o rss= -p #{Process.pid}`.to_i

  puts "Memory: #{((memory_after - memory_before) / 1024.0).round(2)} MB"
end

task.rake

task something_complex: :environment do
  print_memory_usage do
    client = Client.new
    client.run
  end
end