りっぱになったふっかつのじゅもん生成器

pw.rb

#/usr/bin/ruby
require "securerandom"

class Integer
	def stringify(chars, edge_chars, min_digits = nil)
		if self < 0
			raise ArgumentError, "Can not stringify negative numbers"
		end
		unless (edge_chars - chars).empty?
			raise ArgumentError, "Characters need to contain edge characters"
		end
		d = chars.size
		e = edge_chars.size
		x, c = self.divmod(e)
		r = edge_chars[c].dup
		i = 1
		while x >= e
			x, c = x.divmod(d)
			r << chars[c]
			i += 1
		end
		if x > 0
			x, c = x.divmod(e)
			r << edge_chars[c]
			i += 1
	  end
		if min_digits and i < min_digits
			r << edge_chars[0]*(min_digits - i)
		end
		return r.reverse
	end
end

if __FILE__ == $0
	require 'optparse'

	default_length = 16
	cset = {
		:Alphabet => ('A'..'Z').to_a + ('a'..'z').to_a,
		:Numbers => ('0'..'9').to_a,
		:Space => [' '],
		:Printables => (32..126).map{|i| i.chr},
		:Hiragana_dot_bar => ('ぁ'..'ん').to_a + ['・', 'ー'],
	}

	c = []
	l = default_length
	opt = OptionParser.new
	opt.on('-a', 'include lower and upper case alphabet'){c += cset[:Alphabet]}
	opt.on('-n', 'include 0 - 9'){c += cset[:Numbers]}
	opt.on('-s', 'include space'){c += cset[:Space]}
	opt.on('-p', 'include all printable characters (default)'){
		c += cset[:Printables]
	}
	opt.on('--hiragana-dot-bar', 'include hiragana, cdot, and bar'){
		c += cset[:Hiragana_dot_bar]
	}
	opt.on('-l LENGTH', "number of characters (default: #{default_length}"){|v|
		l = Integer(v)
	}
	opt.on('--test', 'run tests'){
		require 'test/unit'
		class TestStringify < Test::Unit::TestCase
			def setup
				@c = ('0'..'9').to_a
			end
			def test_normal
				assert_equal '123', 123.stringify(@c, @c)
			end
			def test_negative
				assert_raise ArgumentError do
					-123.stringify(@c, @c)
				end
			end
			def test_normal_with_len
				assert_equal '0123', 123.stringify(@c, @c, 4)
				assert_equal '123', 123.stringify(@c, @c, 1)
			end
		end
		class TestStringifyWithSpace < Test::Unit::TestCase
			def setup
				@c = ['0', '1']
				@e = ['1']
			end
			def test_normal
				assert_equal '0', 0.stringify(@c, @c)
				assert_equal '1', 1.stringify(@c, @c)
				assert_equal '10', 2.stringify(@c, @c)
				assert_equal '11', 3.stringify(@c, @c)
				assert_equal '100', 4.stringify(@c, @c)
				assert_equal '101', 5.stringify(@c, @c)
				assert_equal '110', 6.stringify(@c, @c)
				assert_equal '111', 7.stringify(@c, @c)
			end
			def test_trailng_edge
				assert_equal '1', 0.stringify(@c, @e)
				assert_equal '11', 1.stringify(@c, @e)
				assert_equal '101', 2.stringify(@c, @e)
				assert_equal '111', 3.stringify(@c, @e)
				assert_equal '1001', 4.stringify(@c, @e)
				assert_equal '1011', 5.stringify(@c, @e)
				assert_equal '1101', 6.stringify(@c, @e)
				assert_equal '1111', 7.stringify(@c, @e)
			end
			def test_leading_edge
				assert_equal '1111', 0.stringify(@c, @e, 4)
				assert_equal '1111', 1.stringify(@c, @e, 4)
				assert_equal '1101', 2.stringify(@c, @e, 4)
				assert_equal '1111', 3.stringify(@c, @e, 4)
				assert_equal '1001', 4.stringify(@c, @e, 4)
				assert_equal '1011', 5.stringify(@c, @e, 4)
				assert_equal '1101', 6.stringify(@c, @e, 4)
				assert_equal '1111', 7.stringify(@c, @e, 4)
			end
			def test_edge_more_than_normal
				assert_raise ArgumentError do
					123.stringify(@e, @c)
				end
			end
		end
		r = Test::Unit::AutoRunner.run
		exit r
	}

	opt.parse!(ARGV)
	c += cset[:Printables] if c.empty? or c == cset[:Space]
	c.uniq!
	e = c.reject{|x| x =~ /[[:space:]]/}
	n = e.size**[2, l].min
	n *= c.size**(l - 2) if l > 2
	if n <=  0
		raise RuntimeError, "Not enough non-space character candidates"
	end
	puts SecureRandom.rand(n).stringify(c, e, l)
end