Random number formatter.
Formats generated random numbers in many manners.
Examples
Generate random hexadecimal strings:
require 'random/formatter' prng.hex(10) #=> "52750b30ffbc7de3b362" prng.hex(10) #=> "92b15d6c8dc4beb5f559" prng.hex(13) #=> "39b290146bea6ce975c37cfc23"
Generate random base64 strings:
prng.base64(10) #=> "EcmTPZwWRAozdA==" prng.base64(10) #=> "KO1nIU+p9DKxGg==" prng.base64(12) #=> "7kJSM/MzBJI+75j8"
Generate random binary strings:
prng.random_bytes(10) #=> "\016\t{\370g\310pbr\301" prng.random_bytes(10) #=> "\323U\030TO\234\357\020\a\337"
Generate alphanumeric strings:
prng.alphanumeric(10) #=> "S8baxMJnPl" prng.alphanumeric(10) #=> "aOxAg8BAJe"
Generate UUIDs:
prng.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594" prng.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab"
Generate a random number in the given range as Random does
prng.random_number #=> 0.5816771641321361 prng.random_number(1000) #=> 485 prng.random_number(1..6) #=> 3 prng.rand #=> 0.5816771641321361 prng.rand(1000) #=> 485 prng.rand(1..6) #=> 3
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 212
def alphanumeric(n=nil)
n = 16 if n.nil?
choose(ALPHANUMERIC, n)
end
Random::Formatter#alphanumeric generates a random alphanumeric string.
The argument n specifies the length, in characters, of the alphanumeric string to be generated.
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 and 0-9.
require 'random/formatter' prng.alphanumeric #=> "2BuBuLf3WfSKyQbR" prng.alphanumeric(10) #=> "i6K93NdqiH"
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 92
def base64(n=nil)
[random_bytes(n)].pack("m0")
end
Random::Formatter#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 “=”.
require 'random/formatter' prng.base64 #=> "/2BuBuLf3+WfSKyQbRcc/A==" prng.base64 #=> "6BbW0pxO0YENxn38HMUbcQ=="
See RFC 3548 for the definition of base64.
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 168
def choose(source, n)
size = source.size
m = 1
limit = size
while limit * size <= 0x100000000
limit *= size
m += 1
end
result = ''.dup
while m <= n
rs = random_number(limit)
is = rs.digits(size)
(m-is.length).times { is << 0 }
result << source.values_at(*is).join('')
n -= m
end
if 0 < n
rs = random_number(limit)
is = rs.digits(size)
if is.length < n
(n-is.length).times { is << 0 }
else
is.pop while n < is.length
end
result.concat source.values_at(*is).join('')
end
result
end
Random::Formatter#choose generates a string that randomly draws from a source array of characters.
The argument source specifies the array of characters from which to generate the string. The argument n specifies the length, in characters, of the string to be generated.
The result may contain whatever characters are in the source array.
require 'random/formatter' prng.choose([*'l'..'r'], 16) #=> "lmrqpoonmmlqlron" prng.choose([*'0'..'9'], 5) #=> "27309"
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 150
def gen_random(n)
self.bytes(n)
end
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 72
def hex(n=nil)
random_bytes(n).unpack1("H*")
end
Random::Formatter#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.
require 'random/formatter' prng.hex #=> "eb693ec8252cd630102fd0d0fb7c3485" prng.hex #=> "91dc3bfb4de5b11d029d376634589b61"
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 53
def random_bytes(n=nil)
n = n ? n.to_int : 16
gen_random(n)
end
Random::Formatter#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”.
require 'random/formatter' prng.random_bytes #=> "\xD8\\\xE0\xF4\r\xB2\xFC*WM\xFF\x83\x18\xF45\xB6" prng.random_bytes #=> "m\xDC\xFC/\a\x00Uf\xB2\xB2P\xBD\xFF6S\x97"
static VALUE
rand_random_number(int argc, VALUE *argv, VALUE obj)
{
rb_random_t *rnd = try_get_rnd(obj);
VALUE v = rand_random(argc, argv, obj, rnd);
if (NIL_P(v)) v = rand_random(0, 0, obj, rnd);
else if (!v) invalid_argument(argv[0]);
return v;
}
Generates formatted random number from raw random bytes. See Random#rand.
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 121
def urlsafe_base64(n=nil, padding=false)
s = [random_bytes(n)].pack("m0")
s.tr!("+/", "-_")
s.delete!("=") unless padding
s
end
Random::Formatter#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.
require 'random/formatter' prng.urlsafe_base64 #=> "b4GOKm4pOYU_-BOXcrUGDg" prng.urlsafe_base64 #=> "UZLdOkzop70Ddx-IJR0ABg" prng.urlsafe_base64(nil, true) #=> "i0XQ-7gglIsHGV2_BNPrdQ==" prng.urlsafe_base64(nil, true) #=> "-M8rLhr7JEpJlqFGUMmOxg=="
See RFC 3548 for the definition of URL-safe base64.
# File tmp/rubies/ruby-3.1.3/lib/random/formatter.rb, line 143
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
Random::Formatter#uuid generates a random v4 UUID (Universally Unique IDentifier).
require 'random/formatter' prng.uuid #=> "2d931510-d99f-494a-8c67-87feb05e1594" prng.uuid #=> "bad85eb9-0713-4da7-8d36-07a8e4b00eab" prng.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.