headers_list

(PHP 5, PHP 7, PHP 8)

headers_listReturns a list of response headers sent (or ready to send)

Description

headers_list(): array

headers_list() will return a list of headers to be sent to the browser / client. To determine whether or not these headers have been sent yet, use headers_sent().

Parameters

This function has no parameters.

Return Values

Returns a numerically indexed array of headers.

Examples

Example #1 Example using headers_list()

<?php

/* setcookie() will add a response header on its own */
setcookie('foo', 'bar');

/* Define a custom response header
This will be ignored by most clients */
header("Example-Test: foo");

/* Specify plain text content in our response */
header('Content-Type: text/plain; charset=UTF-8');

/* What headers are going to be sent? */
var_dump(headers_list());

?>

The above example will output something similar to:

array(3) {
  [0]=>
  string(19) "Set-Cookie: foo=bar"
  [1]=>
  string(17) "Example-Test: foo"
  [2]=>
  string(39) "Content-Type: text/plain; charset=UTF-8"
}

Notes

Note:

Headers will only be accessible and output when a SAPI that supports them is in use.

See Also

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User Contributed Notes 3 notes

up
20
Anonymous
11 years ago
note that it does not return the status header

<?php

header
('HTTP/1.1 301 Moved Permanently', true, 301);

header('foo: bar');
header('a: b');
header('colon less example');

print_r(headers_list());
?>

Array
(
    [0] => X-Powered-By: PHP/5.4.7
    [1] => foo: bar
    [2] => a: b
)
up
10
arnold at jasny dot net
7 years ago
This function won't work for when you're running PHP from the command line. If will always return an empty array. This can be an issue when testing your project using PHPUnit or Codeception.

To solve this, install the xdebug extension and use `xdebug_get_headers` when on the cli.

<?php
$headers
= php_sapi_name() === 'cli' ? xdebug_get_headers() : headers_list();
?>
up
-2
SOLO2
11 years ago
Function to check if a particular header has been added to the list:

<?php

function header_sent($header) {
   
$headers = headers_list();
   
$header = trim($header,': ');
   
$result = false;

    foreach (
$headers as $hdr) {
        if (
stripos($hdr, $header) !== false) {
           
$result = true;
        }
    }

    return
$result;
}

?>
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