Commit 99058c4

@@ -10,9 +10,12 @@ import (
 
 func main() {
 
+	// chose digest function
+	var newHash = md5.New
+
 	// no args, read from stdin
 	if len(os.Args) == 1 {
-		h := md5.New()
+		h := newHash()
 		_, err := io.Copy(h, os.Stdin)
 		if err != nil {
 			fmt.Println(err.Error())
@@ -26,7 +29,7 @@ func main() {
 	flag.Parse()
 	sVal := *s
 	if sVal != "" {
-		fmt.Printf("%x\t\"%s\"\n", md5.Sum([]byte(sVal)), sVal)
+		fmt.Printf("%x\t\"%s\"\n", newHash().Sum([]byte(sVal)), sVal)
 		return
 	}
 
@@ -34,7 +37,7 @@ func main() {
 	for _, filename := range flag.Args() {
 		var (
 			f   = os.Stdin
-			h   = md5.New()
+			h   = newHash()
 			err error
 		)
 		if filename != "-" {