Golang : Find IP address from string

In this short tutorial, we will learn how to get the first occurrence of an IP address in a given string by searching for a matching pattern with regular expression.

 package main

 import (
 "fmt"
 "regexp"
 )

 func findIP(input string) string {
 numBlock := "(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9]?[0-9])"
 regexPattern := numBlock + "\\." + numBlock + "\\." + numBlock + "\\." + numBlock

 regEx := regexp.MustCompile(regexPattern)
 return regEx.FindString(input)
 }

 func main() {

 var ip string

 str := "this is a string that contain IP address 192.168.0.1 and you need to parse it"

 ip = findIP(str)

 fmt.Printf("The IP address in string is %q \n", ip)

 } 

Output :

go run parseipfromstring.go

The IP address in string is "192.168.0.1"