IP2Long And Long2IP

ip.go

package main

import (
	"bytes"
	"encoding/binary"
	"fmt"
	"net"
)

func main() {
	ipList := []string{
		"255.255.255.255",
		"localhost",
		"127.0.0.1",
	}

	for _, v := range ipList {
		long1 := IP2Long(v)
		long2 := IP2Long2(v)
		ip1 := Long2IP(long1)
		ip2 := Long2IP(long2)

		fmt.Printf("origin ip: %s, long1: %d, ip1: %s\n", v, long1, ip1)
		fmt.Printf("origin ip: %s, long2: %d, ip2: %s\n\n", v, long2, ip2)
	}
}

// IP2Long IP To Long
func IP2Long(ipstr string) uint32 {
	ip := net.ParseIP(ipstr)
	if ip == nil {
		return 0
	}
	ip = ip.To4()
	return binary.BigEndian.Uint32(ip)
}

// IP2Long2 IP To Long
func IP2Long2(ip string) uint32 {
	var long uint32
	binary.Read(bytes.NewBuffer(net.ParseIP(ip).To4()), binary.BigEndian, &long)
	return long
}

// Long2IP Long To IP
func Long2IP(ipLong uint32) string {
	ipByte := make([]byte, 4)
	binary.BigEndian.PutUint32(ipByte, ipLong)
	ip := net.IP(ipByte)
	return ip.String()
}