&gt; So either the file already exists and I thus add to it or a new file is created instantly.<p>If you want the same thing but want to do it in an app instead of manually in the terminal you should check out Notational Velocity (<a href="http:&#x2F;&#x2F;notational.net" rel="nofollow">http:&#x2F;&#x2F;notational.net</a>).