ex17.rb

from_file, to_file = ARGV

puts "We are copying data from #{from_file}, to #{to_file}"

in_file = open(from_file)  
in_data = in_file.read

puts  "The input file is #{in_data.length} bytes long"
puts  "Does the output file exist? #{File.exist?(to_file)}"
puts "Ready, hit RETURN to continue, CTRL-C to abort."
$stdin.gets

out_file = open(to_file, 'w')
out_file.write(in_data)

puts "Alright, all done"

out_file.close
in_file.close