require 'open-uri'
require 'fileutils'
require 'ruby-progressbar'

progress_bar = ProgressBar.create(
  starting_at: 0,
  total: nil,
  format: "%a %B %p%% %r KB/sec",
  rate_scale: lambda { |rate| rate / 1024 }
)

content_length_proc = Proc.new { |content_length|
  progress_bar.total = content_length
}

progress_proc = Proc.new { |bytes_transferred|
  if progress_bar.total && progress_bar.total < bytes_transferred
    progress_bar.total = nil
  end
  progress_bar.progress = bytes_transferred
}

open(link, "rb", content_length_proc: content_length_proc, progress_proc: progress_proc) do |page|
  File.open(file_path, "wb") do |file|
    file.write(page.read)
  end
end