title: Unzip password protected zip files in R
body: <p>A password cannot be specified in <code>unzip</code> (<code>utils</code>) function. The other function I am aware of, <code>getZip</code> (<code>Hmisc</code>), only works for zip files containing one compressed file. </p>
  
  <p>I would like to do something like this to unzip all the files in foo.zip in Windows 8:</p>
  
  <pre><code>unzip("foo.zip", password = "mypass")
  </code></pre>