srand

README

srand

😄 Initialize random seed in Golang.

Usage

import "math/rand"
import "moul.io/srand"

func init() {
    // cryptographically secure initializer
    rand.Seed(srand.Secure())

    // simple seed initializer
    rand.Seed(srand.Fast())

    // simple seed initializer overridable by the $SRAND env var
    rand.Seed(srand.Overridable("SRAND"))
    // simple seed initializer overridable by env vars
    rand.Seed(srand.Overridable())

    // cryptographically secure initializer
    rand.Seed(srand.Secure())
}

Install

$ go get -u moul.io/srand

License

© 2019 Manfred Touron

Licensed under the Apache License, Version 2.0 (LICENSE-APACHE) or the MIT license (LICENSE-MIT), at your option. See the COPYRIGHT file for more details.

SPDX-License-Identifier: (Apache-2.0 OR MIT)

Documentation

Overview

message from the author:

+--------------------------------------------------------------+
| * * * ░░░░░░░░░░░░░░░░░░░░  Hello  ░░░░░░░░░░░░░░░░░░░░░░░░░░|
+--------------------------------------------------------------+
|                                                              |
|     ++              ______________________________________   |
|     ++++           /                                      \  |
|      ++++          |                                      |  |
|    ++++++++++      |   Feel free to contribute to this    |  |
|   +++       |      |       project or contact me on       |  |
|   ++         |     |    manfred.life if you like this     |  |
|   +  -==   ==|     |               project!               |  |
|  (   <*>   <*>     |                                      |  |
|   |          |    /|                  :)                  |  |
|   |         _)   / |                                      |  |
|   |      +++    /  \______________________________________/  |
|    \      =+   /                                             |
|     \      +                                                 |
|     |\++++++                                                 |
|     |  ++++      ||//                                        |
|  ___|   |___    _||/__                                     __|
| /    ---    \   \|  |||                   __ _  ___  __ __/ /|
|/  |       |  \    \ /                    /  ' \/ _ \/ // / / |
||  |       |  |    | |                   /_/_/_/\___/\_,_/_/  |
+--------------------------------------------------------------+

Index

• func Fast() int64
• func Overridable(key string) int64
• func Secure() int64

Examples

• Fast
• Overridable
• Secure

Functions

func Fast

func Fast() int64

Fast returns value that can be used to initialize random seed. That value is not cryptographically secure.

Example

package main

import (
	"math/rand"

	"moul.io/srand"
)

func main() {
	rand.Seed(srand.Fast())
}

func Overridable

func Overridable(key string) int64

Overridable will check if the "key" var is configured, else it will return a Fast random seed.

If $SRAND is not parseable, panic is raised.

Example

package main

import (
	"math/rand"
	"os"

	"moul.io/srand"
)

func main() {
	rand.Seed(srand.Overridable("SRAND")) // seed with Fast

	os.Setenv("SRAND", "42")
	rand.Seed(srand.Overridable("SRAND")) // seed with 42
}

func Secure

func Secure() int64

Secure returns a cryptographically secure random seed.

Based on https://stackoverflow.com/a/54491783

Example

package main

import (
	"math/rand"

	"moul.io/srand"
)

func main() {
	rand.Seed(srand.Secure())
}