PHP - Function Header Register Callback

Syntax

bool header_register_callback ( callable $callback )

Definition and Usage

It will register the function that will be called when PHP start sending output

Return Values

It returns true on success and false on failure.

Parameters

Example

Try out following example

<?php
   header('Content-Type: text/plain');
   header('X-Test: f1');
   
   function f1() {
      foreach (headers_list() as $header) {
         
         if (strpos($header, 'X-Powered-By:') !== false) {
            header_remove('X-Powered-By');
         }
         header_remove('X-Test');
      }
   }
   
   $result = header_register_callback('f1');
   
   echo "tutorialspoint";
?>

This will produce following result −

tutorialspoint

The above example will register the header and it will callback the header as a text as shown above