package os2 import ( "math/rand" "strings" ) func GenerateRandomFileName(len int) string { sb := strings.Builder{} for i := 0; i < len; i++ { rd := rand.Intn(26 + 10) if rd < 26 { sb.WriteRune('a' + rune(rd)) } else { sb.WriteRune('0' + rune(rd-10)) } } return sb.String() }