Golang : Convert IPv4 address to decimal number(base 10) or integer

Problem :

IP address in decimal is easier to search, filter or compare. For example, searching for IP address in a given range.

You want to convert IPv4 address to integer to perform bitwise operation or for efficient storage in a database. How to do that?

Solutions :

 package main

 import (
 "fmt"
 "net"
 "strconv"
 "strings"
 )

 func IP4toInt(IPv4Addr net.IP) int64 {
 bits := strings.Split(IPv4Addr.String(), ".")

 b0, _ := strconv.Atoi(bits[0])
 b1, _ := strconv.Atoi(bits[1])
 b2, _ := strconv.Atoi(bits[2])
 b3, _ := strconv.Atoi(bits[3])

 var sum int64

 // left shifting 24,16,8,0 and bitwise OR

 sum += int64(b0) << 24
 sum += int64(b1) << 16
 sum += int64(b2) << 8
 sum += int64(b3)

 return sum
 }

 func main() {

 ipDecimal := IP4toInt(net.ParseIP("98.138.253.109"))
 fmt.Println(ipDecimal)
 }

Output :

1653276013

Is there an easier way? Of course! See this next example :

 package main

 import (
 "fmt"
 "math/big"
 "net"
 )

 func IP4toInt(IPv4Address net.IP) int64 {
 IPv4Int := big.NewInt(0)
 IPv4Int.SetBytes(IPv4Address.To4())
 return IPv4Int.Int64()
 }

 func main() {

 ipv4Decimal := IP4toInt(net.ParseIP("98.138.253.109"))
 fmt.Println(ipv4Decimal)
 }

Output :

1653276013

Happy coding!

References :

https://www.socketloop.com/tutorials/golang-how-to-convert-cast-string-to-ip-address