# pgen.rb
# by Jesse H-K on Thursday, June 15 2006
 
require 'optparse'
 
class Array
    def random_choice
        self[rand(self.length)]
    end
end
 
def parse_options(args)
    options = {}
 
    options[:length] = 10
 
    opts = OptionParser.new do |opts|
        opts.banner = "Usage: pgen.rb [options]"
 
        opts.on("-n",
                "--numbers",
                "Include the digits [0-9] in the password.") do |n|
                    options[:numb] = n
                end
 
        opts.on("-p",
                "--punctuation",
                "Include common punctuation characters in the password.") do |p|
                    options[:punct] = p
                end
 
        opts.on("-u",
                "--uppercase",
                "Include uppercase letters in the password.") do |u|
                    options[:upcase] = u
                end
 
        opts.on("-l",
                "--length=[LENGTH]",
                Integer,
                "The length of the password. Default is 10 characters.") do |l|
                    options[:length] = l
                end
    end
 
    opts.parse!
    options
end
 
class PasswordGenerator
    @@options = { :numb  => ('0'..'9').to_a,
                  :punct    => %w(. , ! ? @ & :),
                  :upcase   => ('A'..'Z').to_a }
 
    def initialize(length, *opts)
        @possible = *('a'..'z')
        @length = length
 
        parse_content_options(opts) 
    end
 
    def parse_content_options(opts)
        opts.each { |opt| @possible.concat(@@options[opt]) if @@options.key? opt }
    end 
 
    def generate
        (1..@length).inject("") { |passwd, e| passwd << @possible.random_choice }
    end
 
    private :parse_content_options
end
 
options = parse_options(ARGV)
 
puts PasswordGenerator.new(options[:length], *options.keys).generate