title: How to check how the web resource is requested?
body: <p>Using PHP, is there a way to check for certain how a web server resource is requested while minimising room for forging and hacking? Or in simpler terms, how to check whether it is a hyperlink click, direct URL, submission of HTML Form, programmatic access etc.?</p>
  
  <p>What about if tools other than PHP is used?</p>