Module: Random::Formatter (Ruby 2.4.2)
Description: Module : Random::Formatter - Ruby 2.4.2

Support for the Ruby 2.4 series has ended. See here for reference.

### Home Classes Methods

### In Files

- securerandom.rb

### Methods

- #base64
- #hex
- #random_bytes
- #urlsafe_base64
- #uuid

### Class/Module Index

Quicksearch

- Random
- Random::Formatter
- SecureRandom

No matching classes.

# Random::Formatter

### Public Instance Methods

base64(n=nil) click to toggle source

SecureRandom.base64 generates a random base64 string.

The argument n specifies the length, in bytes, of the random number to be generated. The length of the result string is about 4/3 of n.

If n is not specified or is nil, 16 is assumed. It may be larger in the future.

The result may contain A-Z, a-z, 0-9, “+”, “/” and “=”.

    p SecureRandom.base64 #=> "/2BuBuLf3+WfSKyQbRcc/A=="
    p SecureRandom.base64 #=> "6BbW0pxO0YENxn38HMUbcQ=="

If a secure random number generator is not available, `NotImplementedError` is raised.

See RFC 3548 for the definition of base64.

                   # File securerandom.rb, line 140
    def base64(n=nil)
      [random_bytes(n)].pack("m0")
    end

hex(n=nil) click to toggle source

SecureRandom.hex generates a random hexadecimal string.

The argument n specifies the length, in bytes, of the random number to be generated. The length of the resulting hexadecimal string is twice of n.

If n is not specified or is nil, 16 is assumed. It may be larger in the future.

The result may contain 0-9 and a-f.

    p SecureRandom.hex #=> "eb693ec8252cd630102fd0d0fb7c3485"
    p SecureRandom.hex #=> "91dc3bfb4de5b11d029d376634589b61"

If a secure random number generator is not available, `NotImplementedError` is raised.

                   # File securerandom.rb, line 119
    def hex(n=nil)
      random_bytes(n).unpack("H*")[0]
    end

random_bytes(n=nil) click to toggle source

SecureRandom.random_bytes generates a random binary string.

The argument n specifies the length of the result string.

If n is not specified or is nil, 16 is assumed. It may be larger in future.

The result may contain any byte: “x00” - “xff”.

    p SecureRandom.random_bytes #=> "\xD8\\\xE0\xF4\r\xB2\xFC*WM\xFF\x83\x18\xF45\xB6"
    p SecureRandom.random_bytes #=> "m\xDC\xFC/\a\x00Uf\xB2\xB2P\xBD\xFF6S\x97"

If a secure random number generator is not available, `NotImplementedError` is raised.

                   # File securerandom.rb, line 99
    def random_bytes(n=nil)
      n = n ? n.to_int : 16
      gen_random(n)
    end

urlsafe_base64(n=nil, padding=false) click to toggle source

SecureRandom.urlsafe_base64 generates a random URL-safe base64 string.

The argument n specifies the length, in bytes, of the random number to be generated. The length of the result string is about 4/3 of n.

If n is not specified or is nil, 16 is assumed. It may be larger in the future.

The boolean argument padding specifies the padding. If it is false or nil, padding is not generated. Otherwise padding is generated. By default, padding is not generated because “=” may be used as a URL delimiter.

The result may contain A-Z, a-z, 0-9, “-” and “_”. “=” is also used if padding is true.

    p SecureRandom.urlsafe_base64 #=> "b4GOKm4pOYU_-BOXcrUGDg"
    p SecureRandom.urlsafe_base64 #=> "UZLdOkzop70Ddx-IJR0ABg"

    p SecureRandom.urlsafe_base64(nil, true) #=> "i0XQ-7gglIsHGV2_BNPrdQ=="
    p SecureRandom.urlsafe_base64(nil, true) #=> "-M8rLhr7JEpJlqFGUMmOxg=="

If a secure random number generator is not available, `NotImplementedError` is raised.

See RFC 3548 for the definition of URL-safe base64.

                   # File securerandom.rb, line 170
    def urlsafe_base64(n=nil, padding=false)
      s = [random_bytes(n)].pack("m0")
      s.tr!("+/", "-_")
      s.delete!("=") unless padding
      s
    end

uuid() click to toggle source

SecureRandom.uuid generates a random v4 UUID (Universally Unique IDentifier).

    p SecureRandom.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594"
    p SecureRandom.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
    p SecureRandom.uuid #=> "62936e70-1815-439b-bf89-8492855a7e6b"

The version 4 UUID is purely random (except the version). It doesn't contain meaningful information such as MAC addresses, timestamps, etc.

The result contains 122 random bits (15.25 random bytes).

See RFC 4122 for details of UUID.

                   # File securerandom.rb, line 237
    def uuid
      ary = random_bytes(16).unpack("NnnnnN")
      ary[2] = (ary[2] & 0x0fff) | 0x4000
      ary[3] = (ary[3] & 0x3fff) | 0x8000
      "%08x-%04x-%04x-%04x-%04x%08x" % ary
    end