#!/usr/bin/env ruby
 
print 'Enter file size (MB): '
the_size = gets.chomp
 
unless the_size =~ /^\d+$/
  puts "Error: bad file size"
  exit
end
 
puts the_size + 'MB file coming right up!'
 
# Generate the file
file_size = 0
string    = "abcdefghijklmnopqrstuvwxyz123456"
 
f = File.new(the_size + 'MB', 'w')
 
while file_size < the_size.to_i * 1048576 # bytes in 1MB
  f.print string
  file_size += string.size
end
 
f.close