title: Find which commit is currently checked out in Git
body: <p>I'm in the middle of a <code>git bisect</code> session. </p>
  
  <p>What's the command to find out which commit (SHA1 hash) I am currently on? <code>git status</code> does not provide this. </p>
  
  <p>Edit: I guess calling <code>git log</code> and looking at first entry works? </p>