title: Bash `install -d` for existing file with same name
body: <p>If a part of my bash script is to copy installation files to a directory:
  <code>install -d DIRECTORY</code> but already there's a file named <code>DIRECTORY</code> , bash reports an error that file already exists. How can I resolve this?</p>
  
  <p>Eg:
  <code>install -d bash_completion.d</code> . Some software, previously installed, has a <em>file</em> name <code>bash_completion.d</code> in the exact same location, so <code>make install</code> fails.</p>
  
  <p>Is the only option to check using <code>if-else</code> or is there some neater way of doing this? Some theory could help.</p>