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    headers_list

    (PHP 5, PHP 7, PHP 8)

    headers_list — Returns 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
    19
    Anonymous
    12 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
    9
    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
    0
    SOLO2
    12 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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