Array.new(8).inject(""){|r|r<<('0'..'z').to_a.shuffle[0]}  # 57
(1..8).inject(""){|r|r<<('0'..'z').to_a.shuffle[0]}        # 51
e="";8.times{e<<('0'..'z').to_a.shuffle[0]};e              # 45
(1..8).map{('0'..'z').to_a.shuffle[0]}.join                # 43
(1..8).map{rand(49..122).chr}.join                         # 34

`pwgen 8 1`.chomp

以下内容对我很有用

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

红宝石1.9+：

ALPHABET = ('a'..'z').to_a
#=> ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z"]

10.times.map { ALPHABET.sample }.join
#=> "stkbssowre"

# or

10.times.inject('') { |s| s + ALPHABET.sample }
#=> "fdgvacnxhc"

试试这个

def rand_name(len=9)
  ary = [('0'..'9').to_a, ('a'..'z').to_a, ('A'..'Z').to_a]
  name = ''

  len.times do
    name << ary.choice.choice
  end
  name
end

我喜欢这条线索的答案，真的很有帮助！，但如果我可以说，它们中没有一个满足我的愿望，可能是rand（）方法。我觉得这不太对，因为我们已经有了Array#choice方法。

require 'sha1'
srand
seed = "--#{rand(10000)}--#{Time.now}--"
Digest::SHA1.hexdigest(seed)[0,8]