title: How a download user checks md5 after file download?
body: <p>We may notice many download sites provide md5 string. For example, when I download <em>ABC.zip</em>, along with an md5 string like: “<code>2743a6a9fe6f873df1c7ed8ac91df5d7 *ABC.zip</code>”. I know the idea behind it, it’s Digest algorithm to prevent file forge.</p>
  
  <p>My question is how a user calculates md5 string for the <em>ABC.zip</em>, and compare it with value site provides? Any existing tool to generate md5 string?</p>