github.com/aclaygray/packer@v1.3.2/common/random/string.go (about)

     1  package random
     2  
     3  import (
     4  	"math/rand"
     5  	"os"
     6  	"time"
     7  )
     8  
     9  var (
    10  	PossibleNumbers   = "0123456789"
    11  	PossibleLowerCase = "abcdefghijklmnopqrstuvwxyz"
    12  	PossibleUpperCase = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    13  
    14  	PossibleAlphaNum      = PossibleNumbers + PossibleLowerCase + PossibleUpperCase
    15  	PossibleAlphaNumLower = PossibleNumbers + PossibleLowerCase
    16  	PossibleAlphaNumUpper = PossibleNumbers + PossibleUpperCase
    17  )
    18  
    19  var rnd = rand.New(rand.NewSource(time.Now().UnixNano() + int64(os.Getpid())))
    20  
    21  func Numbers(length int) string       { return String(PossibleNumbers, length) }
    22  func AlphaNum(length int) string      { return String(PossibleAlphaNum, length) }
    23  func AlphaNumLower(length int) string { return String(PossibleAlphaNumLower, length) }
    24  func AlphaNumUpper(length int) string { return String(PossibleAlphaNumUpper, length) }
    25  
    26  func String(chooseFrom string, length int) (randomString string) {
    27  	cflen := len(chooseFrom)
    28  	bytes := make([]byte, length)
    29  	for i := range bytes {
    30  		bytes[i] = chooseFrom[rnd.Intn(cflen)]
    31  	}
    32  	return string(bytes)
    33  }