// Simple use of text/template and some name-value pair parsing.
package main

import (
	"bufio"
	"io"
	"log"
	"os"
	"strings"
	"text/template"
)

func main() {
	varfile, err := os.Open(os.Args[1])
	if err != nil {
		log.Fatal(err)
	}
	reader := bufio.NewReader(varfile)

	tmpl, err := template.ParseFiles(os.Args[2])
	if err != nil {
		log.Fatal(err)
	}

	vars := map[string]string{}
	for {
		line, err := reader.ReadString('\n')
		if err == io.EOF {
			if line != "" {
				log.Fatal("final var line missing newline")
			}
			break
		}
		if err != nil {
			log.Fatal(err)
		}

		fields := strings.SplitN(line[:len(line)-1], "=", 2)
		vars[fields[0]] = fields[1]
	}

	err = tmpl.Execute(os.Stdout, vars)
	if err != nil {
		log.Fatal(err)
	}
}