genpass.rb

#!/usr/bin/env ruby

DEFAULT_REPEAT  = '10'
DEFAULT_CHARS   = 16
TEMPLATE_NUMBER = '0123456789'
TEMPLATE_SHORT  = TEMPLATE_NUMBER + 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
TEMPLATE_LONG   = TEMPLATE_SHORT + '!@#$%^&*()_+|~`\={}[];:<>,./?"\''

$template = TEMPLATE_SHORT
$chars    = DEFAULT_CHARS

require 'optparse'
Version = '0.0.1'
ARGV.options do |opt|
  opt.banner = "Usage: #{File.basename($0)} [repeats]"
  opt.on('-l', '--long')  {|o| $template = TEMPLATE_LONG }
  opt.on('-n', '--number')  {|o| $template = TEMPLATE_NUMBER }
  opt.on('-c', '--chars count') {|o| $chars = o.to_i(0) }
  opt.parse!
end

def genpass(str, num)
  num.times.inject("") { |r, n| r << str[rand(str.size)].chr }
end

(ARGV.pop||DEFAULT_REPEAT).to_i(0).times { puts genpass($template, $chars) }