title: How do I get the HTML code of a web page in PHP?
body: <p>I want to retrieve the HTML code of a link (web page) in PHP. For example, if the link is </p>
  
  <p><a href="https://stackoverflow.com/questions/ask">https://stackoverflow.com/questions/ask</a></p>
  
  <p>then I want the HTML code of the page which is served. I want to retrieve this HTML code and store it in a PHP variable.</p>
  
  <p>How can I do this?</p>