CODEWITHSUNDEEP
rubyruby-on-rails-3
swapab
swapab

Reputation: 2410

Secure Random hex digits only

Trying to generate random digits with SecureRandom class of rails. Can we create a random number with SecureRandom.hex which includes only digits and no alphabets.

For example:

Instead of

SecureRandom.hex(4)
=> "95bf7267"

It should give

SecureRandom.hex(4)
=> "95237267"

Upvotes: 8

Views: 9227

Answers (4)

natschz
natschz

Reputation: 1117

This will create a number of the desired length.

length = 11

rand(10**length..(10**length+1)-1).to_s

Upvotes: 0

avital
avital

Reputation: 579

length = 4

[*'0'..'9'].sample(length).join

as simple as that :)

Upvotes: -1

Kris
Kris

Reputation: 19948

Numeric id's are good because they are easier to read over the phone (no c for charlie).

Try this

length = 20
id = (SecureRandom.random_number * (10**length)).round.to_s # => "98075825200269950976"

and for bonus points break it up for easier reading

id.split(//).each_slice(4).to_a.map(&:join).join('-') # => "9807-5825-2002-6995-0976"

Upvotes: 2

rossta
rossta

Reputation: 11494

Check out the api for SecureRandom: http://rails.rubyonrails.org/classes/ActiveSupport/SecureRandom.html

I believe you're looking for a different method: #random_number.

SecureRandom.random_number(a_big_number)

Since #hex returns a hexadecimal number, it would be unusual to ask for a random result that contained only numerical characters.

For basic use cases, it's simple enough to use #rand.

rand(9999)

Edited:

I'm not aware of a library that generates a random number of specified length, but it seems simple enough to write one. Here's my pass at it:

def rand_by_length(length)
  rand((9.to_s * length).to_i).to_s.center(length, rand(9).to_s).to_i
end

The method #rand_by_length takes an integer specifying length as a param and tries to generate a random number of max digits based on the length. String#center is used to pad the missing numbers with random number characters. Worst case calls #rand for each digit of specified length. That may serve your need.

Upvotes: 10

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