golang 随机数/域名校验

//随机数生成要用到的

const letterBytes = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"

const (

   letterIdxBits = 6

   letterIdxMask = 1<<letterIdxBits - 1

   letterIdxMax  = 63 / letterIdxBits

)

//domain check

func DomainCheck(domain string) bool {

   var match bool

   //支持以http://或者https://开头并且域名中间有/的情况

   IsLine := "^((http://)|(https://))?([a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?\\.)+[a-zA-Z]{2,6}(/)"

   //支持以http://或者https://开头并且域名中间没有/的情况

   NotLine := "^((http://)|(https://))?([a-zA-Z0-9]([a-zA-Z0-9\\-]{0,61}[a-zA-Z0-9])?\\.)+[a-zA-Z]{2,6}"

   match, _ = regexp.MatchString(IsLine, domain)

   if !match {

      match, _ = regexp.MatchString(NotLine, domain)

   }

   return match

}

//推广id随机生成()

func RandStringBytesMaskImprSrc(n int) string {

   var src = rand.NewSource(time.Now().UnixNano())

   b := make([]byte, n)

   for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; {

      if remain == 0 {

         cache, remain = src.Int63(), letterIdxMax

      }

      if idx := int(cache & letterIdxMask); idx < len(letterBytes) {

         b[i] = letterBytes[idx]

         i--

      }

      cache >>= letterIdxBits

      remain--

   }

   return string(b)

}