Simple Numeric PIN Generator

pin_gen.rb

#!/usr/bin/env ruby
#
# A simple numerical PIN generator.
#   For passphrases, use pwqgen.rb.
# 
# Usage:
#   gem install docopt
#   ./pin_gen.rb --help
#

require 'rubygems'
require 'securerandom'
require 'docopt'

appname = File.basename(__FILE__)

doc = <<DOCOPT
Secure PIN Generator

Usage:
	#{appname}
	#{appname} [-n NUMBER | --number=NUMBER] [LENGTH]
	#{appname} (-h | --help)
	#{appname} --version

Arguments:
	LENGTH      Length of PIN to generate. [default: 6]
	NUMBER      Number of PINs to generate. [default: 1]

Options:
	-h --help                  Show this help message.
	--version                  Show version number.
	-n NUMBER --number=NUMBER  Number of PINs to generate. [default: 1]

DOCOPT

begin
	opt_hash = Docopt::docopt(doc, version: '0.0.1')
	if opt_hash.key?('LENGTH') && !opt_hash['LENGTH'].nil?
		length = opt_hash['LENGTH'].to_i
	else
		length = 6
	end
	if opt_hash.key?('NUMBER') && !opt_hash['NUMBER'].nil?
		number = opt_hash['NUMBER'].to_i
	else
		number = 1
	end

	#seed = 10 ** (length)

	for i in 1..number do
		output = ""
		for j in 1..length do
			output += SecureRandom.random_number(10).to_s
		end
		puts output
	end
rescue Docopt::Exit => e
	puts e.message
end