vim not showing me if I have modified the file
<p>Suppose I open multiple tabs in vim, using <code>tabnew</code>. Now, if I modifiy a file in any of the tabs, vim shows me that I have modified the file by placing a <code>+</code> in front of the tab's title, which happens to be the file's name. </p>

<p>However, when I am editing a single file in vim in iTerm, then I don't see any visual indication to tell me that I have modified the file. Is there a way to get a visual indicator here just like when I open the file in a tab?</p>