new-pass

#!/usr/bin/ruby -w

USAGE = <<__
new-pass [-a] [-s] [#...]

Choose a new password from the alphanumeric set (-a) or the symbolic
set (-s, the default). # is the password length, it can be specified
multiple times for multiple passwords.

The arguments can be intermixed. No arguments is equivalent to -a 8.

One byte from /dev/random is used to select one character from the
set.

Examples:

% new-pass   
I96Cm2OJ
% new-pass 64 8 -a 8   
ttzg!RQya(gN&W2$J,+5i{_f3]Qd^X+9^utI*wfO9xcappr]tGIK]ys:!wQ=,>=Q
GefH>?1<
J2xnNEtU
__

def p(*a) end

unless ARGV.size > 0
  ARGV.unshift "8"
  ARGV.unshift "-a"
end

ALPHANUMERIC = [
  ('a'..'z').to_a,
  ('A'..'Z').to_a,
  ('0'..'9').to_a,
].flatten

SYMBOLS = "~!@#\$%^&*()_+-={}[]|\:\";'<>,.?/"

SYMBOLIC = [
  ALPHANUMERIC,
  SYMBOLS.split(//)
].flatten

raise unless SYMBOLIC.size == (ALPHANUMERIC.size + SYMBOLS.size)

set = SYMBOLIC

open "/dev/random" do |io|
  ARGV.each do |arg|
    case arg
    when "-h"
      puts USAGE
      exit 1
    when "-a"
      set = ALPHANUMERIC
    when "-s"
      set = SYMBOLIC
    else
      pass = ""
      arg.to_i.times do
	b = io.read(1)
	i = b.unpack("c").first
	p [b, i]
	c = set[i % set.size]
	pass << c
	p [b, i, c, pass]
      end
      puts pass
    end
  end
end