It returns a list of response headers sent

Example

<?php
setcookie(“time”,time());
header(‘Content-type: text/plain’);
echo “<pre>”;
print_r(headers_list());
?>

Output

<pre>Array
(
[0] => X-Powered-By: PHP/5.3.3-1ubuntu9.10
[1] => Set-Cookie: time=1337938449
[2] => Content-type: text/plain
)