parse_ip.go

package main

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

func makeSeq(min, max int) []int {
    a := make([]int, max-min+1)
    for i := range a {
        a[i] = min + i
    }
    return a
}

func MinMax(array []int) (int, int) {
    var max int = array[0]
    var min int = array[0]
    for _, value := range array {
        if max < value {
            max = value
        }
        if min > value {
            min = value
        }
    }
    return min, max
}

func parseString(str string) []string {
    var ips []string

    // split with ;
    for _,ipRange := range strings.Split(str, ";") {
        //expand with -
        var octets = strings.Split(strings.ReplaceAll(ipRange, " ", ""), ".")
        if len(octets) != 4 {
            fmt.Printf("Error: %v is invalid ipv4 value", ipRange)
            continue
        }

        var _octets [4][]string
        var _octetsInt [4][]int
        for i, octet := range octets {
            _octets[i] = strings.Split(octet, "-")
        }

        for i,_octet := range _octets {
            for _,_octet_e := range _octet {
                var _converted,_ = strconv.Atoi(_octet_e)
                _octetsInt[i] = append(_octetsInt[i], _converted)
            }
            if len(_octetsInt[i]) > 1 {
                min, max := MinMax(_octetsInt[i])
                _octetsInt[i] = makeSeq(min,max)
            }
        }

        // combine ip address from octets
        for _,_octet1 := range _octetsInt[0] {
            for _,_octet2 := range _octetsInt[1] {
                for _,_octet3 := range _octetsInt[2] {
                    for _,_octet4 := range _octetsInt[3] {
                        ips = append(ips, fmt.Sprintf("%v.%v.%v.%v", _octet1, _octet2, _octet3, _octet4))
                    }
                }
            }
        }
    }

    return ips
}

func main() {
    // var testString = "10.255.250-251.40-45;10.255.250.32;10.255.250.21-22"
    // var testString = "10.250-252.250.40-45 ; 10.255.250.32; 10.255.250.21-22 "
    var testString = "10.250-252.250.40 - 45 ; 10.255.250.32; 10.255.250.21 -22 "

    var listIp []string
    listIp = parseString(testString)
    for _,ip := range listIp {
        fmt.Println(ip)
    }
}