title: Copy all files in a directory to a local subdirectory in linux
body: <p>I have a directory with the following structure:</p>
  
  <pre><code>file_1
  file_2
  dir_1
  dir_2
  # etc.
  new_subdir
  </code></pre>
  
  <p>I'd like to make a copy of all the existing files and directories located in this directory in  <code>new_subdir</code>. How can I accomplish this via the linux terminal?</p>