Use PHP to get all HTTP request headers

Lao Wang

In PHP, to get all the HTTP request headers, you can use the Getallheaders method, but this method does not exist in any environment, for example, you use fastcgi way to run PHP, there is no such method, so we need to consider other methods, fortunately There's something we want in $_server, and it's the HTTP request header that starts with the key name HTTP_:

$headers = array();
foreach ($_SERVER as $key => $value) {
    if (‘HTTP_‘ == substr($key, 0, 5)) {
        $headers[str_replace(‘_‘, ‘-‘, substr($key, 5))] = $value;
    }
}

The code is simple, and it is important to note that the name of the header is not case-sensitive in the RfC.

However, not all HTTP request headers are in the form of keys that start with HTTP_, such as Authorization,content-length,content-type. So in order to get all the HTTP request headers, you need to add the following code:

if (isset($_SERVER[‘PHP_AUTH_DIGEST‘])) {
    $header[‘AUTHORIZATION‘] = $_SERVER[‘PHP_AUTH_DIGEST‘]);
} elseif (isset($_SERVER[‘PHP_AUTH_USER‘]) && isset($_SERVER[‘PHP_AUTH_PW‘])) {
    $header[‘AUTHORIZATION‘] = base64_encode($_SERVER[‘PHP_AUTH_USER‘] . ‘:‘ . $_SERVER[‘PHP_AUTH_PW‘]));
}
if (isset($_SERVER[‘CONTENT_LENGTH‘])) {
    $header[‘CONTENT-LENGTH‘] = $_SERVER[‘CONTENT_LENGTH‘];
}
if (isset($_SERVER[‘CONTENT_TYPE‘])) {
    $header[‘CONTENT-TYPE‘] = $_SERVER[‘CONTENT_TYPE‘];
}

Here by the way how to get the HTTP response header, give a simple example to illustrate the problem:

file_get_contents (' http://www.baidu.com ');
Var_dump ($http _response_header);

There is an easier way to do this:

Var_dump (get_headers (' http://www.baidu.com '));

Getting a response header is much simpler than getting a request header.

Supplemental Documentation: HTTP://WWW.ROOFTOPSOLUTIONS.NL/ARTICLE/223