在Go中,我只想要一个随机字符串(大写或小写),没有数字。最快最简单的方法是什么?
当前回答
package main
import (
"encoding/base64"
"fmt"
"math/rand"
"time"
)
// customEncodeURL is like `bas64.encodeURL`
// except its made up entirely of uppercase characters:
const customEncodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKL"
// Random generates a random string.
// It is not cryptographically secure.
func Random(n int) string {
b := make([]byte, n)
rand.Seed(time.Now().UnixNano())
_, _ = rand.Read(b) // docs say that it always returns a nil error.
customEncoding := base64.NewEncoding(customEncodeURL).WithPadding(base64.NoPadding)
return customEncoding.EncodeToString(b)
}
func main() {
fmt.Println(Random(16))
}
其他回答
func Rand(n int) (str string) {
b := make([]byte, n)
rand.Read(b)
str = fmt.Sprintf("%x", b)
return
}
这是我的方式)使用数学兰特或加密兰特如你所愿。
func randStr(len int) string {
buff := make([]byte, len)
rand.Read(buff)
str := base64.StdEncoding.EncodeToString(buff)
// Base 64 can be longer than len
return str[:len]
}
这里是一个简单而高效的加密安全随机字符串的解决方案。
package main
import (
"crypto/rand"
"unsafe"
"fmt"
)
var alphabet = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
func main() {
fmt.Println(generate(16))
}
func generate(size int) string {
b := make([]byte, size)
rand.Read(b)
for i := 0; i < size; i++ {
b[i] = alphabet[b[i] % byte(len(alphabet))]
}
return *(*string)(unsafe.Pointer(&b))
}
基准
Benchmark 95.2 ns/op 16 B/op 1 allocs/op
/*
korzhao
*/
package rand
import (
crand "crypto/rand"
"math/rand"
"sync"
"time"
"unsafe"
)
// Doesn't share the rand library globally, reducing lock contention
type Rand struct {
Seed int64
Pool *sync.Pool
}
var (
MRand = NewRand()
randlist = []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890")
)
// init random number generator
func NewRand() *Rand {
p := &sync.Pool{New: func() interface{} {
return rand.New(rand.NewSource(getSeed()))
},
}
mrand := &Rand{
Pool: p,
}
return mrand
}
// get the seed
func getSeed() int64 {
return time.Now().UnixNano()
}
func (s *Rand) getrand() *rand.Rand {
return s.Pool.Get().(*rand.Rand)
}
func (s *Rand) putrand(r *rand.Rand) {
s.Pool.Put(r)
}
// get a random number
func (s *Rand) Intn(n int) int {
r := s.getrand()
defer s.putrand(r)
return r.Intn(n)
}
// bulk get random numbers
func (s *Rand) Read(p []byte) (int, error) {
r := s.getrand()
defer s.putrand(r)
return r.Read(p)
}
func CreateRandomString(len int) string {
b := make([]byte, len)
_, err := MRand.Read(b)
if err != nil {
return ""
}
for i := 0; i < len; i++ {
b[i] = randlist[b[i]%(62)]
}
return *(*string)(unsafe.Pointer(&b))
}
24.0 ns/op 16 B/op 1 allocs/
package main
import (
"encoding/base64"
"fmt"
"math/rand"
"time"
)
// customEncodeURL is like `bas64.encodeURL`
// except its made up entirely of uppercase characters:
const customEncodeURL = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKL"
// Random generates a random string.
// It is not cryptographically secure.
func Random(n int) string {
b := make([]byte, n)
rand.Seed(time.Now().UnixNano())
_, _ = rand.Read(b) // docs say that it always returns a nil error.
customEncoding := base64.NewEncoding(customEncodeURL).WithPadding(base64.NoPadding)
return customEncoding.EncodeToString(b)
}
func main() {
fmt.Println(Random(16))
}