Update a xml file of installer information using "MsiProperty.vbs".

Info.xml

<?xml version="1.0" encoding="UTF-8"?>
<Softwares xmlns="http://t2wonderland.blogspot.jp/ns/softwares">
  <Name>Softwares</Name>
  <Version>1.0.0</Version>
  <SoftwareList>
    <SoftwareInfo>
      <MsiPath>data/go1.7.3.windows-amd64.msi</MsiPath>
      <ProductVersion>1.0.0</ProductVersion>
    </SoftwareInfo>
  </SoftwareList>
</Softwares>

xmlupdater.go

package main

import (
	"encoding/xml"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"strings"
)

type Softwares struct {
	XMLName      xml.Name       `xml:"Softwares"`
	Xmlns        string         `xml:"xmlns,attr"`
	Name         string         `xml:"Name"`
	Version      string         `xml:"Version"`
	SoftwareList []SoftwareInfo `xml:"SoftwareList>SoftwareInfo"`
}

type SoftwareInfo struct {
	XMLName        xml.Name `xml:"SoftwareInfo"`
	MsiPath        string   `xml:"MsiPath"`
	ProductVersion string   `xml:"ProductVersion"`
}

func main() {
	for _, xmlPath := range os.Args[1:] {
		infos, err := GetSoftwares(xmlPath)
		if err != nil {
			log.Print("Failed to unmarshal xml: ", err)
			os.Exit(1)
		}

		for i, info := range infos.SoftwareList {
			out, err := GetPropertyValue(info.MsiPath, "ProductVersion")
			if err != nil {
				log.Print("Failed to load propery: ", err)
				os.Exit(1)
			}
			infos.SoftwareList[i].ProductVersion = out
		}

		data, err := GetIndentedXML(infos)
		if err != nil {
			log.Print("Failed to marshal xml: ", err)
			os.Exit(1)
		}

		if err = ioutil.WriteFile(xmlPath, data, os.ModePerm); err != nil {
			log.Print("Failed to write xml: ", err)
			os.Exit(1)
		}
	}
}

func GetSoftwares(xmlPath string) (Softwares, error) {
	infos := Softwares{}
	data, err := ioutil.ReadFile(xmlPath)
	if err != nil {
		return infos, err
	}

	if err = xml.Unmarshal([]byte(data), &infos); err != nil {
		return infos, err
	}

	return infos, nil
}

func GetPropertyValue(msiPath string, property string) (string, error) {
	data, err := exec.Command("cscript", "/nologo", "MsiProperty.vbs", msiPath, property).Output()
	if err != nil {
		return "", err
	}

	// Windows標準出力の末尾の改行コードを削除
	return strings.Replace(string(data), "\r\n", "", -1), nil
}

func GetIndentedXML(infos Softwares) ([]byte, error) {
	data, err := xml.MarshalIndent(infos, "", "  ")
	if err != nil {
		return nil, err
	}

	data = []byte(xml.Header + string(data))
	return data, nil
}