Simple progress bar script without Gem using Ruby.

progress_bar.rb

#!/usr/bin/env ruby

progress = 'Progress ['
1000.times do |i|

# i is number from 0-999
j = i + 1

  # add 1 percent every 10 times
  if j % 10 == 0
    progress << "="
    # move the cursor to the beginning of the line with \r
    print "\r"
    # puts add \n to the end of string, use print instead
    print progress + " #{j / 10} %"

    # force the output to appear immediately when using print
    # by default when \n is printed to the standard output, the buffer is flushed. 
    $stdout.flush
    sleep 0.05
  end
end
puts "\nDone!"