yasl

#!/usr/bin/env ruby

require 'optparse'

run_interval_milli_second = 1000

opt = OptionParser.new
opt.on('-i VAL') { |v| run_interval_milli_second = v.to_i }
opt.parse!(ARGV)
                  
str = ARGV.empty? ? ARGF.read : ARGV.join(' ')
str.chomp.split(/(?=.)/).inject do |run_str, c|
  print "#{run_str}\r"
  sleep run_interval_milli_second / str.length / 1000.0
  run_str + c
end    

print "#{str}\n"