在Go中生成随机，固定长度的字节数组

I have a byte array, with a fixed length of 4.

我有一个字节数组，固定长度为4。

token := make([]byte, 4)

I need to set each byte to a random byte. How can I do so, in the most efficient matter? The math/rand methods do not provide a Random Byte function, as far as I am concerned.

我需要将每个字节设置为一个随机字节。我怎么能这样做，在最有效的事情？就我而言，math / rand方法不提供Random Byte函数。

Perhaps there is a built-in way, or should I go with generating a random string and converting it to a byte array?

也许有内置的方式，或者我应该生成随机字符串并将其转换为字节数组？

2 个解决方案

#1

Package rand

包rand
import "math/rand" 
func Read

func阅读
func Read(p []byte) (n int, err error)
Read generates len(p) random bytes from the default Source and writes them into p. It always returns len(p) and a nil error.

Read从默认Source生成len（p）个随机字节，并将它们写入p。它总是返回len（p）和nil错误。

func (*Rand) Read

func（* Rand）阅读
func (r *Rand) Read(p []byte) (n int, err error)
Read generates len(p) random bytes and writes them into p. It always returns len(p) and a nil error.

Read生成len（p）个随机字节并将它们写入p。它总是返回len（p）和nil错误。

For example,

例如，

package main

import (
    "math/rand"
    "fmt"
)

func main() {
    token := make([]byte, 4)
    rand.Read(token)
    fmt.Println(token)
}

Output:

输出：

[187 163 35 30]

#2

Go 1.6 added a new function to the math/rand package:

Go 1.6在math / rand包中添加了一个新函数：

func Read(p []byte) (n int, err error)

which fills the passed byte slice with random data. Using this rand.Read():

用随机数据填充传递的字节片。使用这个rand.Read（）：

token := make([]byte, 4)
if _, err := rand.Read(token); err != nil {
    // Handle err
}
fmt.Println(token)

rand.Read() has 2 return values: the number of "read" bytes and an (optional) error. This is to conform with the general io.Reader interface, but the documentation of rand.Read() states that (despite its signature) it will never actually return a non-nil error, so we may omit checking it, which simplifies it to this:

rand.Read（）有2个返回值：“读取”字节数和（可选）错误。这是为了符合通用的io.Reader接口，但rand.Read（）的文档声明（尽管它的签名）它永远不会实际返回非零错误，所以我们可以省略检查它，这简化了它这个：

token := make([]byte, 4)
rand.Read(token){
fmt.Println(token)

Don't forget to call rand.Seed() to properly initialize it before you use the math/rand package, e.g.:

在使用math / rand包之前，不要忘记调用rand.Seed（）来正确初始化它，例如：

rand.Seed(time.Now().UnixNano())

Note: Prior to Go 1.6 there was no math/rand.Read() function, but there was (and still is) a crypto/rand.Read() function, but the crypto/rand package implements a cryptographically secure pseudorandom number generator, so it is much slower than math/rand.

注意：在Go 1.6之前没有math / rand.Read（）函数，但是有（现在仍然是）crypto / rand.Read（）函数，但是crypto / rand包实现了一个加密安全的伪随机数生成器，所以它比math / rand慢得多。

#1

Package rand

包rand
import "math/rand" 
func Read

func阅读
func Read(p []byte) (n int, err error)
Read generates len(p) random bytes from the default Source and writes them into p. It always returns len(p) and a nil error.

Read从默认Source生成len（p）个随机字节，并将它们写入p。它总是返回len（p）和nil错误。

func (*Rand) Read

func（* Rand）阅读
func (r *Rand) Read(p []byte) (n int, err error)
Read generates len(p) random bytes and writes them into p. It always returns len(p) and a nil error.

Read生成len（p）个随机字节并将它们写入p。它总是返回len（p）和nil错误。