Detect normal message using regex

@@ -31,15 +31,15 @@ bot.onText(/\/echo (.+)/, (msg, match) => {
   bot.sendMessage(chatId, resp);
 });
 
-// Listen for any kind of message. Translate if it's not a command.
-bot.on('message', (msg) => {
+// [Any normal message which is not a command (not starting with '/')]
+bot.onText(/(?!\/)(.+)/, (msg, match) => {
   const chatId = msg.chat.id;
   const chatType = msg.chat.type;
-  const received_msg = msg.text;
+  const received_msg = match[1];
 
-  // Ignore if input is a command or we are not on a private chat,
+  // Ignore if we are not on a private chat,
   // since direct translation is to be used only on private chats.
-  if (received_msg[0] == '/' || chatType != 'private') {
+  if (chatType != 'private') {
     return;
   }