(PHP 5 >= 5.4.0)
header_register_callback — Call a header function
Registers a function that will be called when PHP starts sending output.
The callback is executed just after PHP prepares all
headers to be sent, and before any other output is sent, creating a window
to manipulate the outgoing headers before being sent.
callbackFunction called just before the headers are sent. It gets no parameters and the return value is ignored.
Restituisce TRUE in caso di successo, FALSE in caso di fallimento.
Example #1 header_register_callback() example
<?php
header('Content-Type: text/plain');
header('X-Test: foo');
function foo() {
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('foo');
echo "a";
?>
Il precedente esempio visualizzerà qualcosa simile a:
Content-Type: text/plain a
header_register_callback() is executed just as the headers are about to be sent out, so any output from this function can break output.
Nota:
Gli header sono accessibili (e emessi nell'output) quando è in uso un SAPI che li supporta.