From: Robert Klemme <shortcutter@...>
Date: 2011-05-11T16:11:46+09:00
Subject: Re: Generate random string matching specific pattern and length

On Tue, May 10, 2011 at 10:56 PM, Kevin <darkintent@gmail.com> wrote:
> I'm trying to generate a random set of strings to fill a database with that
> match the following pattern:  /^([A-Z]|[a-z]|-)+$/
>
> The array I'm trying to create must contain strings that look like
> "A12-34-4567" and be exactly ten characters long I have seen code on the

That's 11 characters btw.

> internet for generating random strings but I don't have internet at home at
> the moment to really study examples like the one here:
> http://coderrr.wordpress.com/2008/10/28/ruby-golf-generating-random-strings

Just a hint: that does not work on 1.9 because ?a does not return a
Fixnum any more.

> I'm guessing that something like map { if  /^([A-Z]|[a-z]|-)+$/  &
> char.len==10
>  strings<< current_matching_value
> }
>
> would achieve the right solution.  Any pointers would be greatly
> appreciated.

Often there is not _the_ right solution (-> TIMTOWTDI).  So far nobody
seems to have suggested good old sprintf:

BASE = 'A'.getbyte 0
DELTA = 'Z'.getbyte(0) - BASE

10.times do
  s = sprintf '%s%02d-%02d-%04d',
    (BASE + rand(DELTA)).chr,
    rand(100),
    rand(100),
    rand(10000)

  puts s, s.length
end

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/