title: How to change content type of Amazon S3 Objects
body: <p>The objects in my Amazon S3 bucket are all of the content type <code>application/octet-stream</code>. Some of these objects are PDFs, sometimes images like <code>JPG</code>, <code>GIF</code>, <code>PNG</code>. How can I change the content type of these objects to <code>images/jpeg</code>, <code>application/pdf</code> etc.?</p>
  
  <p>Can it be done in batch through the Amazon Console?</p>
  
  <p>Can I use the command line?</p>
  
  <p>Or maybe through PHP?</p>