title: How to find a specific change in a specific file in Git
body: <p>I have a file in a Git project that had a specific value changed at some point by someone; I don't know who or when.  I want to find when the change was made, but I'm not sure how I can track that in Git.</p>
  
  <p>I've tried using <code>git diff &lt;sha1&gt; &lt;sha2&gt;</code>, but that shows the differences for the entire project, while I want to check one particular file.</p>