How to generate a random string in Ruby

The following worked well for me




def generate_random_password(min_length, max_length)
length = SecureRandom.random_number(max_length - min_length) + min_length
character_sets = [
('a'..'z').to_a,
('A'..'Z').to_a,
('0'..'9').to_a,
"~!@^&*()_-+=[]|:;<,>.?".split('')
]
retval = []
#
# Add one character from each set
#
character_sets.each do |character_set|
character = character_set[SecureRandom.random_number(character_set.count)]
retval.push character
end
#
# Fill the rest of the password with a random character from a random set
#
i = character_sets.count - 1
while i < length
character_set = character_sets[SecureRandom.random_number(character_sets.count)]
character = character_set[SecureRandom.random_number(character_set.count)]
retval.push character
i += 1
end
retval.shuffle.join
end

For devise secure_validatable you can use this

```ruby
(0...8).map { ([65, 97].sample + rand(26)).chr }.push(rand(99)).join
```