allow variable reference in same env file

main.go

@@ -27,20 +27,18 @@ func main() {
 	}
 	defer envFile.Close()
 
-	envVars := parseEnvFile(envFile)
+	parseEnvFile(envFile)
 	args := flag.Args()
 
-	newEnv := append(os.Environ(), envVars...)
-
 	if len(args) == 0 {
-		for _, envVar := range newEnv {
+		for _, envVar := range os.Environ() {
 			fmt.Println(envVar)
 		}
 		return
 	}
 
 	cmd := exec.Command(args[0], args[1:]...)
-	cmd.Env = newEnv
+	cmd.Env = os.Environ()
 
 	cmd.Stdin = os.Stdin
 	cmd.Stdout = os.Stdout
@@ -56,21 +54,19 @@ func main() {
 	}
 }
 
-func parseEnvFile(r io.Reader) []string {
-	env := make([]string, 0)
+func parseEnvFile(r io.Reader) {
 	s := bufio.NewScanner(r)
 	l := 0
+
 	for s.Scan() {
 		l++
 
 		matches := EnvVarRegex.FindStringSubmatch(s.Text())
 		if len(matches) != 0 {
 			key, value := matches[1], os.ExpandEnv(matches[2])
-			env = append(env, fmt.Sprintf("%s=%s", key, value))
+			os.Setenv(key, value)
 		} else if s.Text() != "" && !EnvCommentRegex.MatchString(s.Text()) {
 			panic(fmt.Sprintf("invalid env syntax on line %d", l))
 		}
 	}
-
-	return env
 }