PHP header_register_callback() Function: Everything You Need to Know

As a PHP developer, you may need to manipulate HTTP headers in your web application. The header_register_callback() function is a powerful tool that allows you to register a callback function to be called when headers are about to be sent to the client. In this article, we will take an in-depth look at the header_register_callback() function and its usage.

What is the header_register_callback() Function?

The header_register_callback() function is a PHP built-in function that allows you to register a callback function to be called when headers are about to be sent to the client.

How to Use the header_register_callback() Function

Using the header_register_callback() function is straightforward. Here is the syntax of the function:

header_register_callback(callback);

The function takes one parameter:

• callback: The callback function that you want to register.

Here is an example of how to use the header_register_callback() function to register a callback function:

<?php

function my_callback($header) {
    echo "Header: $header<br>";
}

header_register_callback("my_callback");

In this example, we define a callback function called "my_callback" that accepts a header parameter. We then register this callback function using the header_register_callback() function. When the headers are about to be sent to the client, the my_callback function will be called for each header.

Conclusion

The header_register_callback() function is a powerful tool for manipulating HTTP headers in your PHP web application. By understanding the syntax and usage of the function, you can easily register a callback function to perform custom actions on headers. We hope this article has been informative and useful in understanding the header_register_callback() function in PHP.